Optimally the inventorry would have unlimited space aand could just be scrolled down ad infinitum to add new items. Either way, the current system is ridiculously small; If I wanted to manage items I'd clean my house. I understand that it may be too difficult and time-consuming to modify the inventory system for it to be feasible make this change for free, but I'd be willing to pay for a new DLC to make the inventory unlimited if that's what it takes
By my recollection this already got a "no" from the devs on grounds of Zoos (among other things) in connection with taking off the PD key cool down, which is basically the same thing. The stance might have changed since then (pre-CE) but I haven't seen anything to suggest it has.
When I played, I was a pack-rat also, at least for the majority of time. Then I had an experience that proved to me that I was being foolish: http://steamcommunity.com/groups/dodcr/discussions/0/792923684091178203/ You don't have to go to the extremes that I and others did for this run. But it does prove that the available inventory space (not even counting the near-infinite storage of your pocket dimension) is more than sufficient, if you can simply practice a bit of self-control and greater wisdom as far as what is and is not worth holding on to.
Managing invenory takes WAY too much time. As long as craft materials don't take space it would be fine.
My main problem is that I pick up a bunch of useless junk gear just to sell to Brax in case Brax has a useful item for sale. A simple increase gold spawn+no selling setting would fix the whole thing for me.
