Hi 04jharrison, some excellent posts & advice.
At Ryanair you are likely to be flying around the maximum 900-1000 hours per year. It would be advisable to at least stay 2-3 years and get your full ATPL ie unfrozen, then it would be easier to move on if you wished, also you don't want to give the impression you are quick to jump ship. That said several of my former modular students have been there (Ryanair) many years as it's relative quick to get a command (5 years possible) whereas some other airlines 10 years plus.
Recently Ryanair also took a limited number of UK licensed FrATPLs supposed to be starting type rating soon.
Your last sentence sums it up well and as you said earlier avoid MPL schemes.