The core glTF specification requires that the baseColorTexture be an 8-bit sRGB texture, so if you’re hoping to use a 32-bit texture in that material slot, it isn’t officially supported. But I would check with whatever engine/viewer/runtime you’re using, you might get lucky and they support 32-bit PNG textures anyway.
Aside from that, the alternative would be to define a custom extension or patch the support into the tools you need, and just accept that your file will be non-standard. Not sure whether that approach would be acceptable for your use case.