If he plays for us then he stays for the season, or goes back to Stockport at the end of January. It would seem pretty high risk, I think, to use our first team to see if he can make the step up, or to be able to see it in any meaningful way, which would require more than a brief run out in the FA Cup.
If we see him as either a player for the future, or an asset to be sold, then he needs to be playing regularly. It doesn't really make a lot of sense for us to scupper his development in the middle of what has been a fantastic season for him just to give him 10 minutes here and there.