If I am building, I use certain colours, I go collect that colour rock. Then stuff it all into a bunch of my crafting tables so yeah, there is an actual need to have more than a handful of 'm. And 4 refineries is suspect? Wow, then I better watch out then since I’ve like 5 or 6? (only 3 under power). Also have 2 forges, 3 extractors, 2 compactors, 4 mixers, etc., etc. under power and a small area with like 10 to 14 machines with just spark. If you do a lot of different things, you have a lot of mats that need processing!
And in all honesty, this is not an exploit whatsoever. XP eventually gains you cubits, it’s how the game works, if they change that to only buying them I will quit the game. I’ve been buying way too many cubits as it is which would already have been less if they finally added a way for PS4 players to upgrade to the Deluxe edition. But besides that I spent way too much, there are plenty of ways to gain XP fast. You want to nerf XP mining as well then I suppose? If I go out mining and need more plots and thus cubits I skip the persisting pie and go for a teaching and easily level 2 to 3 times in 1 mining session if not more.
And yes, I do sometimes use the ‘stuff crafting tables with rock’ to level up my main (already level 50 on 3 skillsets, currently have 320 skillpoints I can’t use) or one of my alts a bit more quickly, the latter is usually not so much for the cubits but to have a higher level alt quicker. Thing is, it’s a boring thing to do, I rather go mining, hunt, build, etc. Sometimes it just works and wouldn’t want to see it nerfed.
I could live tho if they somehow add a way for alts to level quicker or change the whole skills an skillset thing so I don’t even need alts. I also would like an alternative method of gaining plots, like once the economy is working with the future patches that we can use coin to buy them. And perhaps tokens or something with either cubits or coin or both that we can use to level an alt to say level 25-35 in 1 go but you already have to have 1 char that’s level 40+.
If I had to spend more money on this game than I already have to be able to do what I want then the game is most certainly going in the wrong direction. I’m happy to give the devs as much money as I can and only a few days ago was the last time I did, but sjeesh, this would most definitely ruin my fun and I will most certainly go spend my money somewhere else if I have to wait on real life events in order to do something in the game (a game on which I’ve already spend 100’s of euros) something is wrong. And with waiting on real life events I of course mean waiting until end of the month to get my income, haha.
Not a pushback, a cancelation please. I do not want recipes to change, perhaps minor tweaks here and there but not huge ones. If they want us to use up certain mats and if rock is one of them they will need to find a way to make them usable.
Like signs, loved them, but basically used the same sign (cool slate, Gellis’ own), never needed to make that many. Loved, loved the addition of a gazillion sign materials and now all of a sudden I’m always in need of more ink because I’m using all kind of different ones.
So, what if they added new decorative textures, heck not just 1 or 2 each for each stone, no, let them add like 20 for each. This means we will be going to want to be turning those refined rocks into more than 1 kinds of decorative variant and thus we need more rocks!
I prefer those type of ways to ‘balance’ the game then the ones you are usually suggesting 
and gives also players indirect possibility sell xp to others.