At Harrenhal weren't there a few knights asking why we didn't attend the Tourney after we beat Harwin?
If we lose we can watch the rest of the tourney, if we win we can reveal ourselves afterward, even if we don't get the knighthood. Either way that could set up that we're definitely doing tourneys and build more rivalry with Criston. Given our taking part in a Trial by Combat and training openly, I'm kind of assuming that our "mystery knight" thing is likely to be an open secret rather than something genuinely concealed. If
@Teen Spirit tells us that being in the Tourney doesn't count to the expected to attend either the Feast or Tourney then I'll switch my plan to watching the Tourney.
Attending the feast seems like a waste of action economy to me. I'd like to keep our host happy (be at feast or tourney), talk to one of Royce or Arryn, progress our knighthood ambitions (watch tourney, attend tourney, or train), and progress something else - dragontraining, or Alicent romance, or talk to Gwayne about Alicent and if he'd be okay faking a courtship with us to cover for us courting Alicent. If attending the tourney counts that'd be best, but we're always tight on actions and we're going to need to find time for at least some of those other things and this seems like a good place to try.