You can never seal sapwood well enough to stop checking especially if it is thick, it has to come off if you remove the bark.
I would plan ahead, pick a time when the weather is pleasant for cutting, splitting and removing bark and sapwood and put the tree on the ground.
Back in my early bow making days I would try to cut corners, cut a log and short stop the whole process by leaving the trunk whole, bark untreated, bark off but sapwood left on and numerous other osage transgressions. Lost a lot of mighty fine wood to my carelessness.
Everything I cut now gets the complete treatment from trunk to shellacked, sapwood free staves before I put them up to cure. An osage stave, once collected, is a very special thing to me, I treat it with the respect it deserves.