Milestone Recovery, my houserules

My latest houserule is as follows:

For every two combat encounters played through the players receive 1 Milestone. A Milestone can be spent to recover your level in hit points, heal 1 point of ability damage to every stat, and to recover 1/4 (rounded down) of daily abilities. Spells recovered are spell that you have already used and you do not get to select new spells. You can not go over what you would normally have and any going over your normal allotment is lost. The exception is spells. If you would recover a spell slot, you may choose to recover a lower level spell slot instead.

You may spend two Milestones to recover twice your hit points, heal 2 points of ability damage, and recover 1/2 (rounded down) of your daily abilities. Four Milestones recovers four times your hit points, 4 points of ability damage and all your daily abilities.

Milestones can be spent at any time. This includes in combat during another persons turn. For example, say that you are struck and reduced to -12 hit points. You may spend a Milestone and gain enough hit points to survivce. Or say that you are at -3 and stable for several rounds and you decide that you need to get back up. You can spend a Milestone, instantly heal and be ready to fight again.

Pros: This reduces the need for players to constantly retreat and rest. Many plots can be undermined by the players constantly being forced to leave and rest. Any kind of plot with urgency that involves multiple enocunters benefits greatly from this 'resting without resting' idea. Or any kind of plot that involves the players surviving some kind of gauntlet also benefits. It also gives the players more options and the ability to pull out more resources when needed. This system also doesn't sacrifice the whole resource management aspect of the game, just extends it.

Cons: The gives the players an extra reward for fighting encounters and may steer players towards fighting more battles that they could have otherwise avoided. Instead of confronting the enemy they might run back to a room of minions in order to get a Milestone. It also introduces the idea of fighting more battles in order to recover a specific needed ability. For example, the players teleport into a dungeon, fight some bad guy, but then need to fight more encounters to get the teleport spell back so they can leave. Also, players can do more out of combat type spells if they are fighting that day and that is a little weird. Being able to identify more items because you had several fights is odd.

The future: I initially envisioned this as getting 4 milestones every 4 encounters, but in making these rules I wanted to apply to 4th edition also where you might run more encounters. I also wanted it to be possible for players to run out of resources despite the Milestones even though it would be much harder. So I think I might change this to getting a 1/3 Milestone every 2 encounters which would be equivalent to a full rest every 6 encounters. The reason I started with a full rest every 8 encounters was to minimize any disruption to my game and get a sense of how this playtested.