Will GGG ever increase our inventory size?

I can see why they want to keep with the "classic" small inventory. Not my favorite thing about the game, but not a huge deal.
A way around this would be to sell, as a Microtransaction, a portable "Currency" tab which can hold one single stack of each type of "Currency".
Simple, straight forward, pays for itself, and does not actually disadvantage anyone not able to pony up the cash.