I've had a 12t shorty hyd jack that cradles the axle tube next to the U bolt or it also has a adapter that cradles the U bolt.
Axle tubes on Leaf spring suspensions have a thick wall and will not crush or dent/bend next to the U bolts. Torsion axles have a thin wall
When replacing tires on my trailers like others I jack one side at a time and let the axle down on RR tie blocks under the U bolts.
Most of the time I take the trailer in and let the tire dealer do their thing.
Both of my tire dealers are set up to handle trailers of all types.