I have talked to several tanks that have walked a way from playing the character because of the Bulwark check. I play a tank and I'm not sure I will continue for long unless the check is removed or modified to be less intrusive. The call can come at the worst time and normally does. It comes during the long cast of an Ascension.It comes when I need to joust, move, side-step, rescue a mob from another player or when a boss just drained all your mana. It is a horrible check and is killing groups and discouraging users from even playing the class.
You can cast Bulwark WHILE casting another ability. So if you're casting an ascension, for example, you can still hit bulwark right away. Unfortunately, if the art your casting finishes while bulwark is casting, bulwark will cancel.. because recovery time interference. (This isn't a defense of the mechanic, just information to help you deal with it).
This is easy to fix. Macro your Bulwark, and add a command just above it in the macro that says /cancel_spellcast
You don't NEED to cancel your spell cast for bulwark. It will go off WHILE you're casting something else.
But you said: If you use a macro with /cancel_spellcast then you won't have to worry about the first thing finishing. Since getting Bulwark cast is more important than a few seconds delay on an Ascension, I'd prioritize that.
It's generally not an issue with ascensions, since they take so long to cast. It tends to happen more with regular arts. And some of those, like death saves and reflects, are equally as important as bulwark at times.
If you actually cancel the spell (prior to bulwark) recovery doesn't apply. Recovery is after finishing a spell/combat art, not after starting.