[Q] S-OFF impossible after going S-ON? topic

In response to my Q below, a user wrote that if I go S-ON (to take the phone into repair) I can never go S-ON again. Is that true? I've restored my phone 100% to stock HBOOT, recovery OS etc. and I'm presently at HBOOT 1.57 and have locked the bootloader and have "*** LOCKED ***". So the only thing left is to go S-ON. But I'm wondering if this means I can never go S-ON again.

Thanks!

The original question: http://forum.xda-developers.com/htc-...hboot-t2999854