It may be that the only thing you can do is to reduce the piece count, thus reducing the polygon count in the 3D program. Delete any pieces that will not be seen in the render.

It also depends on the format and exporting options. Formats like OBJ take a lot of resources and time to be exported, event more with logos as it doesn't support transform and of course instances.

Another trick you might try is to hide sections of your model. Mecabricks doesn't export hidden pieces in my experience. So you can group manageable chunks and then export them one at a time. The best part is that when you import them they will show up in their original positions, so you shouldn't have
to maneuver the chunks to put it back together again.

I tested it with the colosseum set https://www.mecabricks.com/en/workshop/r121kqW7vlB. I tried exporting wavefront obj with logo and got an error. Then I grouped everything but the stage and then hid that group. It exported just fine.