Does the PHQ have any construction limits

[Nosscar]

I have been building up my PHQ, with hull parts, ore refinery, water, energy cells, and a few more.
I have just got blueprints for the engine parts factory too, but i just cannot snap it anywhere, even if i put new connectors and t-blocks down, it just will not snap, does the PHQ have a limit as to how many production modules you can lace, and yes they are all well with the plot square.