Is it possible to build maps unlimited large?

In how far is S&Box restricted by the limits of Source 2 and what is actually right about the possible map sizes of Source 2 and S&Box?
I read in a Source 2 Discord that it says that you can build outside of the grid, but no entities can leave the grid?
Is that true and wouldn’t that again restrict the maps to a certain size like in Source 1 with Garry’s mod?
Or are there techniques with which one can still build larger maps than the given grid in Source 2?

I am confused because I constantly get vague information from everywhere that is somehow partly correct but then somehow not.

Maps are currently limited to the same size as source 1, this is a limit Garry mentioned he wants to raise in the future.

You can find more info here or ask in the discord.