How to remove adhered nylon from build platform?
One important and missing aspect of your question is what is your build platform? Glass is likely to give you the best results, while aluminum has some risks, depending on your choice of solvents.

My hasty research at first showed Glacial Acetic Acid to be a candidate, but as a very strong acid, it will require some care in use.

I found a pdf document with a comprehensive chart of possible solvents for nylon. The above noted solvent (100% acetic acid) lists with an Unsatisfactory result. I read this at first as being unsatisfactory for dissolving, but the correct interpretation is that nylon is unsatisfactory for being resistant to this solvent. Additional notes show nylon will dissolve in this solvent.  I have a bottle of white vinegar (acetic acid) but the panel reads as five percent concentration, almost certainly ineffective for your purposes.

There are other solvents listed as unsatisfactory, which points them in the right direction for your purposes. A couple of them are in the chlorine family and no reference is made regarding concentration. Chlorine of even weak concentration will attack aluminum very quickly.

Despite the weak concentration of the white vinegar, I've dropped a segment of 3 mm nylon to see what happens overnight and may report via an edit here later.