When cloning the WC-51 abp to create a new one sporting the DShK, the marker extension will stop working, most likely because there is no corresponding .mua or .muax or wherever the markers are stored anymore.
That is true sadly. I encountered the same issue and don't know any solution.
This is quite amazing, I was not aware of this whole possibility.
Is this theoretically possible with every vehicle that supports mounted machineguns? For instance, could I mount a DSHK MG on a universal carrier instead of the Vickers?
Theoretically yes, although the Universal Carrier is the only vehicle that uses a new hardpoint for the vickers and not using the mounted gun. So it looks a little different:
P.S. - If anyone does know how to properly enable / add belgian gates (like the ones in the "All Units" Mod) I would be stoked for them to help me on discord @TacoLite#7647 since I am clearly incapable of adding them on my own lol.
You can clone this tank trap:
ebps\races\german\buildings\defensive_structure\tank_trap
and then edit the blueprint to:
environment\objects\defenses\metal\belgian_gate_01\belgian_gate_01
The .sga file should be located in "C:\Users\NAME\Documents\my games\company of heroes 2\mods\tuning". Can you build your mod and confirm it's saved in there? Then startup the game and check again. I had the issue once that the game removed the .sga file because the mod contained a change which wasn't allowed (an edited .mua file in my case).
I only tested with one weapon in the .abp at a time, but I don't think those conflict. The first screenshot looks like the weapon state is wrong. Is the hardpoint enabled?
Here I guess you are asking if the DShK 38 can be mounted on the Dodge or the Brem Carrier. The answer is no to both. Dodge only supports the .50 cal and Bren Carrier only the Vikers.