Never would happen as converting coin to credit would be a profit loss. I hate having coins the whole of it is pointless tbh because of credits.
My problem with the coins is they have no purpose other than upgrading gear, and playing in coin games to win.....more coins, lol. Just dumb/redundant imho.
What if they made seasons for each tier and the player would have to use coins to buy into it. A hack for instance would buy in for 500 coin while a legend would need 5 million to enter the season. In the season you would only play against those within your tier. The rewards could be discounts on Turf passes or discount on balls for another season something to promote sales of something while giving the player something of value that can be used. When playing season games you could be locked into that tiers player level of WGT gear - so the level 80s with level 80 gear that are hacks can not be playing with level 10's with much lower level gear.
I dunno but I think something on these lines would be much better for the game overall.