We have a 1000+ innings on Jamo, we know what he is at this point. He wasn't as bad as he was last year and he isn't as good as he's been so far this year. I'm very much on the move Belli & Taillon train for financial freedom and build around the rest of the team.
As to your question, there's two avenues. Which avenue is best is dependent on what they do at hitter.
1. If they spend big on a bat(s), go the cost controlled SP trade route. It's time to spend prospect capital.
2. If they miss on Soto for example and go the route of trading for a bat or spending less on a bat in FA, swim in the waters of the high end SP FA market - Burnes/Flaherty/etc.
As much as I appreciate how solid Jamo has been this year, I don't believe his performance will be repeatable next year. I fully expect the MLB to make changes to the ball again in favor of offense after this disaster of a season league wide and I expect that to pile on to Jamo's looming regression next season. It's not the end of the world if we keep Jamo, but we're more than likely paying $17m aav for a low 4 ERA the next two seasons.
Next season is fixable, but it's going to take Jed moving some chess pieces around and getting aggressive this offseason in FA and with moving prospect capital.