Not quite sure if it was in the preview or browse mode, but when I pressed the up and down rig buttons I could select an amp and get all the rigs with that amp. However, some profile makers choose to call the amps for example Brit 800, and then they won't be there with the amps actually called Marshall JCM800.
Well, being able to search for "800" would be ok in this case. I need to get a few more flying hours with this unit, but so far so good. Reamping with spdif was a bit of an adventure, but it worked.