There is often a seafood, and rarely a veggie, option on the J menu. If you do not eat meat at all, I'd recommend you pre-order a special meal (seafood or one of veggie choices: VGML, VLML, IVML, AVML).

Why do you think special meals are not as good? Many times they are better than regular meals.

As for BTC, keep in mind it only applies to the main dish. All other elements of the meal will be the same as the regular meal. I've asked for a BTC plus a seafood or veggie meal (for the other courses), but SQ invariably gets that wrong or refuses to do it.