Can anyone offer any advice on this? Are the above values safe to use without permanently damaging the unit's clock generation in some way?
I've used 100 MHash/s steps a lot for testing/fine tuning individual ants. No harm done. 
It is quite comfortable but has one astonishing problem... it only accepts multiples of 25
I wanted to try frequencies like the earlier reported 262.50mhz but that's a no go.