Here's my Feedback on the current "Gear Gate" being applied to the events. This is the hard requirement for having characters at 6* & gear 6 before you can attempt them.
I understand that theres a need encourage players to develop characters beyond stars, but this takes away freedom and strategy for how players develop there teams.
A far better approach would be to increase the difficulty of these stages. Either through extra stats, modified abilities or even extra enemies.
In that way the suggested requirement can be gear 6, but players could use strategy and maybe find a combination of characters, gear lvl and skills that works for them.
Maybe gear 7 for one but 5 for another. That requires more evolvement from the player and a feeling of being challenged not held back.
Tower mode are a good example of this, there is the restriction of types but no restrict on anything else. The mode is still extremely challenging and the community is engaged in finding the best way to beat these stages.