I am thinking about this a lot of time. That this game lacks of flexibility and very low as F2P friendly.
For example I have an idea that why not allowing unlimited loot tickets for players above level 65. Reason: to reach this level need a huge lot of time and huge lot of mindless grind. And having it everyday really kills all the last drops of fun. But obviously there are lot of big spenders who above level 65 and spend money for WE and loot tickets. So making it free will affect sales (so will never be implemented). F2P can’t compete in any kind of challenges here (just truth, without money you can’t be top1 in challenge event or so). So let’s set limit - unlimited loot tickets if only you haven’t buy anything within last three months. I am almost sure spenders will not stop spend to get unlimited loot tickets (second possible limit - just season 1 stages). While F2P players will have big relief from boring grind and less stress so they will be more happy to play (and to continue watch mv, and to save players activity instead of “I am already pissed of bad summons and grind - I am quitting”).
Second possible idea - increased 5* chances from tc20 to players above (let’s say level 50) and who not spend money for 6 months for example. Reason: F2P will be happy to get 5* to play with while ordinary 5* already out of competitive for a long time so it’s not affect anything generally except that F2P will have little more comfort and interest. I am absolutely sure F2P players will not start to spend money - just quit or find other game.