I'm no AV guru or Korrak's xp wizard, only did Korrak's like 10 times and haven't been in AV prior to that for years. So some of what I say may be wrong or it may be how it currently is and I'm unaware. Instead of awarding a blanket amount of xp for winning/losing award xp for "participating". Let's assume today the max amount of xp you can get from AV is 1000 since I like small numbers
I heard there's "ticking" xp? Not sure if that's accurate or not, if it is I'd remove it or nerf it. Then:
Let's say capping a tower/bunker/gy or being within range while it's being capped gives 250xp
Participating in the Galv/Bal kill gives another 250xp
Doing x amount of damage/healing (I don't know what an acceptable amount for this would be because of lack of experience) gives 250xp
Winning gives 750xp
Losing gives 100xp
If I saw this in patch notes as an AFK'er my new minimum would be to be at least in range of the tower/bunker/gy cap, at least tag Bal/Galv, do x damage/healing so I'd have to stay with the group. That will only get me 3/4ths of what I used to get though. I could opt to AFK at this point and receive my 3/4 xp or I could try to get a victory and get 500 more xp, which would be a 50% bonus to today's current xp values.
This could all be shit, I'm no game designer lol But you get what I'm saying right? XP rewards for activity instead of blanket XP.