That's what hot bars are for, hence the name. Instead of clicking to open an element, clicking to get what we want, clicking to close the element, or auto closing on use, we have an icon for that item on the hot bar, so we just click/use the hot key for that item. If only I'd suggested something to make getting to the different pages easier, wait, I did, in the post you quoted here, but, for some reason, you chose to edit that out for your response.

Ctrl 1-5 to get to a specific page, once on that page, 1-0 for the top bar, and maybe Shift 1-0 for the bottom bar on that page. Since we're Turn Based, that latter bit may not be strictly necessary, you can just as easily click the appropriate icon on that page, and that wasn't included in my previous post. Hot keys for swapping bars was. I have also mentioned having the items/skills/spells that aren't on their own bar already on Page 1, for easier access to them, but again, since we're TB, I'm not sure what difference it would make, but it would be easier to access them.

Yes, some management, and initial set up is required. However, contrary to your claim, you did have to set up your bars in BG 1 and 2 for sure. My cleric wouldn't be using the same items and spells as my wizard, which wouldn't be using the same stuff as my rogue, which wouldn't be using the same stuff as my fighter. This means I'm setting up equipment, ammunition and spells, where applicable, to every character, including not having any spells at all where a class didn't have any spells. Inventory and hot bar management are part of the game, even on TT, where hot bars aren't an issue, they're not a thing. However, you do have to manually set up your spells per day. As I also said earlier, doing this is literally preparing my spells for the day. Once I have items assigned to their appropriate slots, for me, I don't have to redo it every time, on that character. I do have to add new spells, or hot key new arrows, if I'm using them, etc., but that's part of the game, which is far superior to having them automatically added, and then having to sort them where I want them.

As far as size goes, yeah, they could let us adjust it. Not all of us are 20 years old, with excellent eyesight. I'm about to be 20 for the third time.