We don't operate in a schedule circumstance of consistency. Any given category open time or lack of is not constant. It will ebb and flow over a career. Same with all the other components of schedule alterations.
There is real danger in altering a PWA with what will likely be permanent 'fixes'...irreversible in most cases, to address what is a transient and probably 'perceived' circumstance in any given category.
There are many variables feeding into our monthly schedules. Lack of posted open time doesn't mean there are no opportunities to alter ones schedule. It just means one has to exploit the next tier of opportunity in things like swaps and open WS.....in base and out.
If those opportunities are unsatisfactory, we all have the option to alter the schedule equation by repositioning ourselves in base or fleet.