I will try to go in depth with the problem with out of party (oop) stacking and I will try to showcase what each approach to making it work has in favour and against it:
This means that the healing applied in the area scales linearly. Having 6 kegs in place for example would lead to ~1800 heal/3s. That is equivalent to another healer spamming their AOE cast heal for all affected people in the area. In comparison, WP's Martyr's Blessing heals for 300/s with a 23% uptime (3s/13s) vs Engi's 100/s with 88% uptime (15s/(15+2)s). Not to mention that WPs cannot do any other actions while they are channelling that ability.
Pros:
-Fun for the Engies
-Easy implementation
-Easy server computation
Cons:
-Even with a 24target-cap, stacking Engies would lead to VERY strong out of warband support parties (that would most likely break rvr balance)
To avoid the above issue, one solution would be to make the oop heal value be a lot lower than the in-party heal value. To properly balance it, in the case of 24target cap, you'd probably aim for a oop heal coefficient between 5% and 20% (15 to 60 heal).
Pros:
-Easy implementation
-Fairly easy server computation (1 extra calculation to check whether the heal comes from an in-part Engi or not)
Cons:
- Numbers may be too low for the ability to be enjoyable (low number spam on screen)
- Nearly useless unless stacked
- Full oop heal with value cap system:
Another solution would be to make the oop heal value cap system. As I will soon show, the major limitation here is the additional complexity this adds in terms of in game calculations. Therefore, simple value cap systems are prioritized.
The simplest would be a softcap system, similar to the Morale damage system that is active now (
https://wiki.returnofreckoning.com/Morale) where the softcap is based on a decaying meter system. You can imagine a similar approach for Bugman's Best where oop healing is allowed, but after reaching a specific heal value (e.g. 900) which decays by a certain amount every second (100/s) the healing coefficient from the same ability would be reduced (to around 5% - 10% of incoming value).
Pros:
- Fun for Engies, since it can impact on both party and oop/wb.
- Balanced, based on the specialized softcap system
Cons:
- Depending on timing (when the decaying/s value is deducted) you could see only some of the Engies actually heal people --> unfair heal contribution (relevant for zone contribution and in-game killboard)
- Hard computation (2 extra calculations: Constantly-updating individual decaying heal value compared to softcap for all players affected and check on each heal for whether to apply the reduced coefficient or not) --> potential server strain and lag on big fights (?)
- In case you'd like to differentiate between party and oop engineer healing (maybe so as to eliminate the first con) even more checks and flags are required.
- Potentially hard implementation (too much effort for a single ability?)