cosmetic idea
you have probably already thought of this, and i guess you could monetize this and probably will, ( though i hope for the best) each season for getting a certain rank maybe gold like the normal game you guys could issue out a reward in the form of a really cool board, i would say little legend but i feel like those would be better monetizations, boards will show everyone that look at me i was able to hit such and such rank.
perhaps you only need to just play ranked until you get placed to get said board skin and then you get chromas for each higher rank you attain ending with a prestige chroma for the board at a very high rank.
my FIRST idea of a board that comes to mind that i feel would be amazing and i think it fits the hexagonal unit placement areas well would be either a hextech theme or a P.R.O.J.E.C.T theme