What type of schedules are feasible as a Senior FO? Will that change greatly under new reserve rules and PBS (drop to zero, etc)?

Is there a push for senior FOs to upgrade, or are pilots at Spirit left to their own devices?

Spirit is on my short list as a final stop. I'm hoping to "retire" in 13-18 years which makes every year count. I'm certainly willing to upgrade when the time is right, but I'm doing my "worst-case" planning as if it will never happen. Due to my age I'll never max a legacy CA group/pay scale (just too many younger pilots there already). I don't need to make $250k per year anyway and think I'd prefer to make about $150k with a phenomenal QOL. Thus, higher pay sooner with good retirement contributions and good QOL later are more important to me than end-of-career pay.

I'm being told that once I have enough seniority, my QOL options will allow doing "retiree" things while continuing to work, so my plan of retiring by 55 doesn't make much sense (and the QOL is why so many pilots work until mandatory retirement date or medical issues cause retirement).