Ok. Taking back what I've said somewhat. Larian allowing long rest at will still doesn't work. There are so many short rest mechanics negated by unlimited long rest.
So, unlimited short rests are fine. Players should short rest after every battle to recover using Hit Dice. Hit Dice prevents HP recovery abuse. That's their purpose. Short rests reset superiority dice, Action Surge, Second wind, etc., thus adding meaning and purpose to the fighter. They can endure a lot more punishment and may even carry the team until long rest is available. Short rests allow other abilities to reset too. Wizards can even use Arcane Recovery to regain a set number of spell slots. So it's not just HP recovery. Short rests make it so the heroes can keep fighting longer in a single day without rest.
Long Rest, therefore, should be what is limited. My suggestion here is that Larian makes Long Rests earned and cumulative.
I played Tabletop using BG3 characters, True D&D 5e stats, items, rules, etc. and what I learned from the Afflicted story playthrough of BG3 is that you dont need to long rest after every fight. The story was completed up through the harpy fight and the whole grove, and the Long Rests were as follows:
Long Rest allowed after Intellect Devourer fight on the beach. That's a nasty fight. Even though Day 1 wasn't very long, after that fight, it makes sense to rest especially if the devourers are done right. Again, you need at least 4 level 2 PCs to defeat 3 Devourers using genuine 5e stats. Day 1 can be explained as heroes finding a good campsite, etc. after their stressful journey through Hell.
Second Long Rest should be after fighting Marli and Barton. Until you fight them, Long Rest should be restricted unless you saved it from earlier.
Third Long Rest after Grove is totally completed, harpies, goblins and all.
So, I suggest players earn long rests as they adventure, like rewards for good gameplay. You beat intellect devourers and earn 1. You don't have to use it, but you can. Let's say you dont. You save it. You fight Marli and Barton, Now you have 2 long rests you can use at any time. Lets say you even make it through the grove without a single long rest. After Nettie, you gain a 3rd long rest, but you use 1. You still have 2 saved.
Then things go bad. The owlbear almost kills you. You spend another long rest. Gobbos in Blighted almost kill you. Long rest again. Now you are out. No more long rests. Fight Spider Queen. Get 1 long rest. Use it. 0 Long Rests again. Can't long rest again until another milestone completed.
And again, every time you long rest, things change. Maybe the three tieflings are no longer caring about their lives and futures but are doing something else...etc. Someone nee like Mol interrupts the ritual, buying more time.
