There’s a saying in hifi hobbyist circles, where some people spend thousands on new components for a minimal performance gain: “the best upgrade you can make to your system is some new music”.
Translated to bikes, I guess this could mean “spend your money on whatever will help you enjoy your cycling the most”. Given that you already have a trail HT, will having another one, off the peg and made of titanium, really make that much difference? Could you consider a custom steel frame, or a road bike, or a fat bike, or a FS, or a foreign cycling holiday?
Good luck in Afghanistan and you and your mates come back safe.