Object limit in forge

I have a question about an apparent object limit in Forge. Twice while using forge (in Forge World), I reached an apparent object limit while still being well within the “budget” that is given to you. The first time I was trying to make a large area of submerged walkable surface (so players would be waist deep in water). I ended up using interlocking Y platforms. However, I was unable to finish it (or even get started on the actual structures). I still had plenty of my budget left (a bit over 8000 I think), but forge wouldn’t allow me to place any more items. The second time I was trying to make lanes for a race game (using double walls), and once again I reached an apparent object limit while still having a lot of budget left.

So my question is, what is the capped # of placeable items in Forge? I understand the need for an object limit (I’m sure having someone place 1000 items would be a bit of an issue). I would just like to know the object limit so I can better think out maps and game types.