Obviously there is a limit, but if you think this guy can stay close to healthy, extend him before he prices himself out of Henry's comfort zone.
I'm thinking 3 year $48mill as a starting point. He's making about $5.75mill now, but has only put up 7.5 bWAR over the past 3 seasons, largely carried by his 6.1 bWAR in 2021. Teoscar Hernandez is a good comp with 8 bWAR in the past 3 seasons, and he got $23.5mill for one year. O'Neill's injury history should affect his AAV, but Hernandez is definitely be his ceiling. If O'Neill prefers years over money, he might go for a multiyear deal now rather than risk being derailed again and taking less than the much more durable Hernandez.
But maybe I am not being realistic. mvp comes up with some extension ideas that are probably more realistic, leaving the debate on them only on the minutiae of the offers.