Well, I hope you could at least please pass on these suggestions to the developer then.
And among these suggestions I think the TitanRO guidebook is something that you can work in since it's specific for this server.
I'd like all the features myself and aside from the important crashing bugfixes, I chose these specific features as the minimum base level of features needed to at least play the game casually. Like for example, aside from fancy UIs of PC, mobile character creation almost contain the minimal barebones needed to get the same PC experience. It just needs that "rotate character" preview and it will be functionally the same as PC without the pretty fluff of aesthetics. And most importantly it is probably relatively easier to implement too I assume which is one the main benefits of these suggestions in my opinion.
If I'd rank the most necessary features of my suggestions it's having a Map Indicator because some quest are unplayable without it. Followed by WOE effects because this game heavily features skills it stands to reason to at least provide a way to have an indication that said skills are in use. Probably the next would be the rotate character preview but only because it is the only thing missing to make that section of the game complete functionally speaking.
The mobile app may just be the most convenient thing to persuade newcomers to try the game at least nowdays because of surge of mobile popularity. People who may not be interested in investing time in the game due to having limited access to PC can do so at the comfort of their own smartphones whenever and wherever. I think its important to look into this now more than ever at least in my opinion.