No!. Sanding sealer isn't meant to go over stain. Just put clear coat over stain.

I don't know why your 1K rattle can causes the stain to blotch. I'm not experienced at all with acrylic sprays apart from painting a few DIY effects unit cases, but people have used clear acrylic sprays over stains on this forum for years without any issues that I've noticed.

If you start with a couple of very light sprays, I'd have thought that should be enough to seal the surface for some wetter spraying. But maybe others will comment.

What is the 1K spray you have used before?