5 minutes of adventure and 24 hours of rest nonsense
Its kinda fascinating how hard you stick to this (your own) headcannon, even tho you dismiss it as nonsense with the same breath. O_o
After 1 long rest from the time you visit the inn, it should be burnt down.
After 3-6 (whatever they think fits best) long rests from when you arrive at the grove, the ritual should be complete or something else should happen to restart it again.
After 2-3 days of ignoring Lae'zel and not finding her Gith patrol, she should temporarily leave.
Same with Wyll and the goblin leaders.
After you trigger the hag/Mayrina side quest, every time you long rest, a redcap or some other minion should be generated and placed in your path before you get to her in her lair and she comments on how it took you SO long. She was growing bored and impatient.
After 3 days from the landing on the beach, you have your first Dream Lover dream, but you have it sooner if you actually used tadpole powers. After that, you have another in 6 days unless you use tadpole powers repeatedly. Then you have the second 1 day sooner per use of powers. After that, same as second dream.
Interesting ideas ... +1 to all.
This is humorous to me.
First, let me say, that it is not headcannon, as you keep accusing. It is based on literal gameplay. I have played the game multiple times through, and I have literally rested, run through Moonhaven to Risen Road, and had one of my companions say, "It's been a long day. Let's get some rest," or something similar. This scenario has happened more times than I can count. The companions nag me to long rest when we haven't even done anything, or especially after a single battle. AND unless I actually DO long rest that often, I miss out on certain companion dialogues. Also, I HAVE played it this way on numerous playthroughs because I can and I want to make sure I'm not missing anything (like new companion dialogues). It is 100% fact that you CAN play it this way, and frankly you SHOULD play it this way if you want to not die when you first play through the game.
You see, long-term players like us who have been playing this game since it came out for EA know what to expect and can push the long rests out easily enough. No problem. But what about new players? What is their experience?
Here's a real example of a new player's experience - one of my family members:
Crash on the beach. Meet Shadowheart. Fight 3 intellect devourers. Doesn't know anything about them. Is playing a fighter. Rushes up to the nearest with her longsword and shield. Hits. Doesn't kill the first. Gets attacked and is taken out in one round. Uses Shadowheart to kill them. Barely survives. Long rest. Meets fishermen. Fights them. Bad RNG. Long rest because dang things went poorly. Reaches dank crypt and fights Gimble and company. Tough fight. Long rest. Fights Mari and Barton and company. Another near-death experience. Long rest. Fights skeleton mages. Nearly dies. Long rest. Reaches the grove at the gate and rushes into battle. Nearly dies. Long rest even before entering the grove at that very moment for fear that if she enters the grove she might trigger another fight that will finish her off.
This is BAD RPG'ing. It is why I keep constantly saying they need to revamp encounters. You are supposed to fight easy, baby monsters at levels 1 and 2 so that new players can learn the game well. Instead of fighting imps and intellect devourers at levels 1 and 2, we should be fighting baby thralls and lemures and manes and other easy enemies so that we can learn the game system without getting pummeled by monsters with resistance and special attacks and so forth. New players should be able to reach the grove on a single run without needing to long rest, or at the very least a single long rest. But instead, the encounters are designed to challenge experienced players right from the beginning even allowing players to attack cambions and mind flayers. (Now, mind you, I don't mind ALLOWING such things, but my point is that the design of encounters is way overpowered. If it wasn't they wouldn't have nerfed imps and intellect devourers.)
Anyway, the point is that it isn't headcannon. It's legit, and it has happened more than once to people I know. Also, I've seen others post the same sentiment. The game is designed for you to, and promotes you to, long rest after each fight. 5 minutes of adventure, and 24 hours of rest.
Now for the other part. I find it a bit humorous that you found it interesting and +1'd it when I've said pretty much the same thing numerous times before and you resisted it because I called it timed events. I changed it to "story-based changes" and suddenly you +1 it.
Still didn't trip up Icelyn though.

In regards to this, I can't tell you how stupid it is for me. I'm not picking on Larian with this. I recently played through the Stag Lord base in Pathfinder and found the same thing occurring. I'm going into the Stag Lord's base, kill a bunch of his guys, spend days returning to the outpost and resting and healing, and I return to find it just the way I left it. I thought to myself, "You've got me on timed quests to make sure I complete this mission in a set number of days, which makes sense and all, but then you let me kill a bunch of Stag Lord minions and spend days resting and return with NOTHING having changed? That makes no sense at all. THAT is what we mean by "video-gamey". If it was a real RPG with a DM, the DM would be like, "Fine. You can return to the outpost, rest and so forth, but I can guarantee to you that the entire place will be on alert the time you return. Guaranteed."
This is what I'm talking about with BG3. I'm not asking for, "You must rescue the grove in 3 days or the tieflings will be kicked out and the ritual will be complete," or, "You must go to the gith patrol by Day 2 after you meet Lae'zel or she leaves your party permanently." I'm just looking for things to make sense such as, "If you long rest after you arrive at Waukeen's Rest and see it burning, the fires are out and you don't rescue the counselor." Why? Because it makes sense that if you see a burning building and you do nothing, it'll burn down and you've missed your opportunity, ESPECIALLY if you decided to spend the rest of the day napping after you first saw it burning. You should not be able to return to it 3 days later and still see it burning and still be able to rescue the counselor. Nothing about that makes any sense.