I think it's a mistake to have made Doch gul so strong AND so slow to obtain if it could some how have been made with the time expectancy as say edl, it wouldn't make future boss winning so heavily skewed in a long reign of uncontested server dominance (Assuming 2 clans were edl equipped some what evenly prior to dg). It's too late to fix dg now imo without throwing off a "balance". Making all quest armors only have a level req would fix level lock punishing players who should be past lower quest armor bosses but not fix level lock punishing players who should be past lower raid bosses which I would argue is more important. This is unique to celtic heroes. Instances could fix that to a degree but it would to some extent devalue overworld bosses. Unless instance bosses were completely different but also their drops competitive to over world bosses.
Principally a game shouldn't punish higher levels imo and principally monopolization of bosses shouldn't exist imo. Assuming level lock absolution. Without level lock, monopolization will exist. With level lock, it's possible for monopolization to exist just a lot harder to achieve. With level lock higher levels and older players are punished. Without level lock, lower levels and newer players aren't even in the question. As well earned as dedicated relentless longer playing players may be. It shouldn't leave others option less (instances). I don't know what can really satisfy everyone.
If you don't want to be affected by level lock but want to be 100% damage efficient on 220 bosses. DONT put yourself in risk of leveling more. There are people who accidentally level higher than 220 whether by a ton of bossing or bounties <--(which I don't see as something that the player can't take responsibility for). You have to realize that you have more control over whether you level more than what OTM decides to change in game design. No one is 233 without bounties and floor bosses.
I tried to write all my thoughts sorry for the big wall if you are going to reply read it all though

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