I am really not sure why an endorsement is really neccesary.
...a nosewheel it did make things a little easier (too easy) but had the effect of producing less compeptent Pilots. Now to get T/W endo all you have to learn are few different techniques such as;
The Rudder pedals are not footrests
How to make a proper balanced turn
The correct approach speed
How to hold off and flare correctly
And there you go....
Mind you, I am in full agreement that tailwheel trained pilots know how to use rudders. I am the first to admit, as a nosewheel trained student, I was woefully lacking in this area.
Everyone should have some time on a
conventional u/c airframe