Paint and Body Subframe seat brace question

[limp]

The instructions for my MM subframe connectors say to remove the existing rear seat bolts and use the bolts supplied by them for the seat braces...
My car has studs there and I wondered why I can't just leave them if they are long enough? They look like they might be a pain to get out.....
Whats everyone else done.??

 

[AeroCoupe]

Clean the threads under the car with a wire brush, spray with Liquid Wrench, double nuts on the top side and back them out.