First house rule from my P2e remaster game, offered for your review.
Spell Slot Heresy
Since Pathfinder is balanced at a per encounter level, per-day limits on daily abilities are largely only kept around due to tradition. And tradition is just peer pressure from strangers, I don't see a good reason to follow it.
Any spellcaster can recover spent spell-slots with a one-hour activity, as noted below, while characters with focus points can recover them during combat.
Recover Magic
Traits: concentrate, exploration, manipulate Requirements: You have expended a spell slot or used some other once-per-day activity
You spend one hour to recover your expended magical power.
During such time you may not work on any other activities or actions or be treated for wounds. At the end of the hour you regain spell slots or once-per-day abilities as per your daily preparations. If you have cast spells from a wand or staff, the item also regains any expended uses or charges.
If you are a prepared spellcaster such as a cleric or wizard, you may not replace what spells you have prepared for the day.
Refocus (1A)
Traits: concentrate, flourish, manipulate Requirements: You are missing at least one focus point.
You take a moment to perform some deed to restore your magical connection, such as touching a talisman, speaking a phrase, or simply taking a breath. Doing so restores 1 Focus Point at the end of your turn.
EDIT: For the record, please presume the above is all released under the ORC license as a derivative of Player Core 1.
If I squint, I can kinda see the argument for essentially short rest spell recovery. An interesting change, to be sure.
I heavily disagree with making focus points recoverable in combat though. The whole point of them is to be once per encounter, that's how they're balanced.
Except that you can gain up to 3, and there is the champion "Desperate Focus" feat allowing them to recover during combat as a free action. (With caveats in PC2).
Can you think of an example 1-A or 2-A focus spell that would be horribly unbalanced if a character was able to just cast it every round? Compared to that same character's alternatives with runed weapons, spell slots, scrolls, or wands?
I could see adding some kind of similar constraint - or making it a reaction where the trigger is if the previous focus spell failed it gives you a flat check to regain the focus point.
As for examples -
Fire Ray - fire domain clerics are now neverending flamethrowers.
Ki Strike - every turn a monk can now do ki strike flurry of blows to have +1 and 1d6 extra on both strikes.
Hand of the Apprentice - wizards can become backline melee at range - thor hammers fly every round
Additional edit:
The change to recover magic would also pretty much destroy any need for resource management - if I'm a caster why not just dump every spell slot I have in this current fight, rest an hour and then do it again? Clerics could just dump all the heal spells from their healing font after combat to heal everyone up, then rest an hour and regain them all and do it again next fight.
Extra Additional Edit:
Both of these changes sound like fun cheat codes to make the players win, but it pretty much removes all challenge.
To paraphrase Thurston Hillman, GM of Rotgrind and Associate Publisher at Paizo:
If your party needs to do their daily preparations, but it doesn't make sense narrarively for them to take a 9+ hour break, let them refresh their abilities anyway!
Focus Spells are "easier to use" spells that, relative to full slotted spells, should be easier to use. Since spell slots moved from "wait until the adventuring day is over" to "have a pause during exploration", it seemed appropriate to move focus points from "have a pause during exploration" to something easier, meaning "during combat."
Since it burns actions to do nothing but recover a single focus point, having it be as complex as casting a fireball (2-A) seemed excessive. So, 1-A is where I landed.