[nbartlomiej]

The "refresh" button randomises as much as it can, but you can prevent a section from being randomised by "locking" it (clicking on the tiny lock icon).

So you can pick a size, lock it and hit "refresh" as much as you wish. I'm glad that you like the app, cheers!

[ctdonath]

Ah, didn't realize "refresh" was randomizing my prior-chosen settings; thought it should just re-apply those settings to the randomization process.