The only possible catches are that if you end up with a 30 hour layover it could potentially reset the clock, but that's not common at all, and that they can assign the days off however they want.

In my experience though, that pattern resulted in 17-18 days off because they would give me a rest day around every 4 days to keep me legal for 4 day trips that may come available. Sometimes they would do it at the 3 day point if that day fell on a day with high coverage and they had sequential days of low coverage to follow.

You are also automatically released at noon on your last on call day if not on assignment (short call is not an assignment) prior to a hard non fly day. You have to ask if it's a soft non fly day but I never had them deny it for me.

Hard non fly days are says you request after bid awards that you can't be extended into (they call them golden days). Any golden days awarded during a stretch of days off count as being at the beginning of that stretch with the caveat that days you are off via trades are not golden days even if a golden day was traded.