The biggest issue with oasis is they sum to a wide uncaring about their f2p player basis a total uncare to what comes together with the implementation of a new feature.

The ti tools nerf for example wasn't a bug, just a direct consequence of the introduction of ultimate training and charms, but when oasis gave the ok to it didn't ask to the chinese developers what would have been the consequences of doing so and didn't warn us beforehand.

The same very likely happened now, with 4.0 and cave keys.

Before ultimate training implementation brothers farewell tools had only gold secondary stats and with an higher tier than the current ones. Red gourd secondary stats were comparable or better than ninja tool essence. De facto, whoever had the chance to get and reforge tools at that time owns 30-40 more secondary stats per tool and own tons of +4 elemental resistances.