I think it depends on why you’re following the psak. If you’re looking for someone who is matir something, and R’ Emden zt”l is matir, I’d say no. We are not supposed to look around for heterim.
If your Rav told you to look up and see what R’ Emden held, then I’d say it’s fine. You’re not really looking to follow R’ Emden – you’re following your own Rav.