Foam filled tires can be removed from the steel rim with some difficulty, cleaned up, and the rims reused. The individual would have to decide which way to go, reuse or new.
(Just put a little brake fluid or better yet thinner on the rubber to eat it off.) Sorry, the devil made me do it!!!
Foam is pretty expensive for rear tires in situations where there is fast tire wear.
I was unaware that tires could be retreaded while filled with foam and mounted on the wheel. That could be an economical move if that service is available in your area.
Unless you are getting large punctures in your front tires in severe (loader?) service (larger than Slime and such can plug) then Slime is an excellent inexpensive alternative to foam fill. Slime will handle all the small punctures from thorns, nails, and similar sized problems. In general if a standard tire path (not a boot) will fix it, so will slime. With Slime you can dismount the tire, clean out the Slime, and send through ordinary recap process.
Pat