Max,
You're more than welcome to stay. It's up to the troupe as to how much retooling you can do for Onesiphorous. My opnion, since he hasn't played much is that he could be entirely redone. You can redo him from scratch up to 30 years, post gauntlet, and then you can advance him for the 2 years 1220 and 1221, and make plans for 1222. You won't get many xps for the 1220 princeps season, but you'll get some.
1222 is kinda stalled at some point in the summer, I'm not pushing events past summer of 1222 until the stories there are resolved. I believe, but i'd have to go back and look that Onesiphorous has a princeps season in 1222, it can be handwaved or I can do a story for that season for him.
1222 summer and later is going to see a huge political schism developing within the Order. Apollodorus was effectively unmasked and had been previously identified as an agitator by House Guernicus due to his hobby of investigating the House's tendency to cover up issues. His subsequent assassination, which took place in The Fall of Night is going to have repurcussions for the forseeable future. Whether the political schism develops into something more confrontational remains to be seen.