This turned kinda long, so i came back and did the intro again to warn everyone this is not an amazing text, is just long. I expressed my opinions on the options we have to vote and gave an option of my own design of what I think would be a good state for the pit taking balance, replayability, challenge and punish into consideration. I kind of knew what i said was achievable with RO engine before writing it so is not far fetched in any way, and if you wanna insult me because you readed this and gained nothing then refer to DM's to not ruin the topic.
Go!
Problem: Recovery conversion is too punishing
So I think this is the major reason why people don't like the mechanic of RC (And Reflect on a similar vein) is the punish behind it, some people mentioned before and it's kinda obvious that it doesn't feel good when you missclick in a big pile of effects and heal a monster from 10% to 100% effectively ruinin the hard work of your Sacrifice GX (Or dying with reflect).
Solutions: Many imo
I can think of several solutions to different degrees of what you wanna achieve and I think different people will have different choices when they have to come up with a way to deal with a singular problem, so I will develop my opinion on the existing options and maybe throw in something of mine to the mix.
1. Fixed resistances. Meaning every mob has certain types they take 100% from and rest 25%, no heal from lower damage and no randomness
I don't like this idea, but not because it doesn't work in fact it may be the best one if all you want is efficiency, but I belive is food for no brain play and what I mean with this is that it ruins the idea of keeping people engange on what they are doing, every damage type will get a target and they just gonna deal with it, plain and simple. Also boring in my opinion, but seems efficient on paper.
2. Recovery Conversion but visible on the monsters
So this is winning the votation by a slight margin, why? clearly because players like punish, but what kind of punish? Fair punish which comes in the shape visibility. How much punish tho? If I can see the monster immunity and I missclicked anyway because the game is a mess of effects (because I like my effects thank you very much) that would feel bad anyway, to be the guy who ruined the Sacrifice GX dps would feel bad or good if you are a bad person. So even if Recovery Conversion remains as the choice I would think tunning it down would be ideal. I will developed visibility ideas on a different point that are also applicable here.
3. Controlled randomnes
I already heard someone rolling his eyes and I am still writing this. This choice is a mix of both before and developing it even further, I would have some monsters immune to X types of damage and to differentiate they would be color coded, green is immune to ranged, black is immune to melee and blue is immune to magic(This is applicable to option 2). But a little punish keeps everyone on their toes so lets make some monsters randomly get Recovery Conversion this way we make sure no one class can dominate the server, but it will only recover a small % of damage (I don't wanna say a random number but 25%-50% sounds about right, req testing) so you gonna make your party life harder but they may be able to deal with your mistake and instead of being dmg type based (Because we have those done and with colors) it can be something else, why not AoE? this way we deal with sharpshooting killing 2/3 of the monsters or any other heavy aoe hitting class, and to indicate RC on we use a Icon on top of his head and it doesn't matter if you see the monster specifically, as long as you see the icon you know that your aoe skill will heal something and you should stop it until single target dps cleans the problem.
Conclusions?
So, I think every solution may work, the third one clearly needs much more work put into it but i went beyond the question and options because if pit is gonna be the great endgame, then it should be something where a party really organizes itself and coordinates to do it, if the killing gets too slow because of this, maybe a buff to drops is in order, maybe a system that spawns a miniboss on the map after certain kills on the pit, or minibosses with random skills (from a selected pool) roam the map with a higher drop % of the good items, daily quests to kill certain mob types for X rewards, if Lunar can truly go crazy in this piece of content to make it fun, durable and rewarding without destroying the server economy, we should support that and give meaningful feedback, specially the people that does the content and plays the game very regularly.
If you lasted this long reading, thank you.
PD: sorry for any typos, format mistakes and also Fix Rudo card please.
