First off blueloctite ALL threaded connections. Mount and antenna!
My opinion is an antenna on a spring hard mounted to an nmo directly to the machine somewhere would be my reccomendation. Even if you have to weld a mount tab to the machine. The antenna will be able to bend and deflect alot of impacts that way at least until the very base of it gets smashed. Im currently running two mxta26 antennas on heavy iron, one on a 390 size trackhoe, and another on d6 dozer. Both of which have held up fine but concrete dust is starting to corrode one of them pretty badly. I'm a big fan of the mxta26. My two have been going for about 3 months now no issues. But I really like the idea of a ghost mount as well as that would be easy to fit on a skidsteer but I feel like if it hit something it wouldn't be resilient at all.