When building grids in the workbench, there currently only are 10 slots in the toolbar. This isn't much considering the amount of blocks, making it quite tedious when building, constantly having to go back to the blocks list menu to switch the toolbar around.

I suggest 2 improvements - that are already used in Space Engineers - to make it much more potent :

1- group blocks. In Space Engineers, similar blocks are grouped together, a group only taking 1 slot and the mouse scroll wheel switching between blocks of the same group. For example basic cubes (full cube, half cube slope...) are grouped together

2- have several toolbars, selected with Ctrl+[number] or Shift+[number]. Allowing several toolbars would allow further groupings and quickly changing between then. Once more this feature is in Space Engineers and Stormworks could make a great use of it.

Those 2 upgrades would massively increase the amount of blocks you could have at hand, without going back to the blocks list menu. You could for example put all armour blocks in one toolbar, all tubes in the second one, all engine parts you need in the third... switching very quickly once you've set them up.