Can you mix acrylic polymers and monomers from different brands?

Yes, you can do it but is it a good idea? No. What would happen if you reduce the yeast by half in a bread recipe? Or double it? Something would happen, but what is not predictable. One thing IS for sure, it's not the same recipe now.

Polymer contains Benzoyl Peroxide (BPO) which like yeast is a catalyst in the chemical reaction. It has to be exactly matched to the monomer to get a predictable result that the chemist designed both for.

Otherwise, you can get under curing or over curing. Over curing will simply make the result less reliable and increase lifting. But under curing is worse, because that is an allergy risk and thosands of Nail Technicians lose their career each year because they developed allergies. .