Sorry, I forgot to check here.
I tested the MOD again, but it seems there are still some issues.
The crash when placing/removing the PY beacon has been resolved. But now, the beacon disappears when it is removed.
Also, when I mentioned the "special pipe" last time, I was referring to the straight pipes, elbow pipes, and T-pipes from the MOD Flow Control.
It seems that the game crashes when trying to auto-place one of these pipes while holding normal pipe.
The common point in both issues seems to be a mismatch between the surface entity and the inventory item.
In the case of the PY beacon, it exists in the inventory as an "AM1FM1" setting, but when placed on the surface, it operates with different settings.
As for the Flow Control pipes, when a T-pipe (or similar) is manually removed, it turns into a normal pipe in the inventory.
Also, when the game crashes during auto-placement of a T-pipe, I noticed that the number of normal pipes in the inventory decreased. If I had no regular pipes, the crash did not occur.
It seems that in Flow Control, pressing the Q key on a placed T-pipe brings up a normal pipe, which may be related to how the items are handled internally.
Please take your time. I’m happy to wait patiently.