>>1030854rear coaster is not designed to do real descends. A mild incline would be fine. They can break quite aggressively. You'll have no problem blocking the rear wheel.
On long, steep descends, the hub just gets hot and melts away the grease.
Did this once to a F&S Single Speed hob from the 60s. At the end the thing bled out its grease and I never got rid of the squeaky sound while breaking (would have had to change the break-cylinder presumably).
So, yes, you'll be fine.
