In my experience 3Com cannot put the license of one model to another laso with contract.
Only with sositution (contract or not) with 3Com and only with the same model of NBX, 3Com put the license without its bougth.
Infact if you have V3000 and change and buy another model you must buy all the license to put in new NBX.
this point is very interesting, because also the nbx is different but all is from 3Com, and in a more years i don't know if this is possibile, i buy another way all the licnese i bought in past,i hope in the future...
For the restore of backup (configuration) i try to put the backup of NBX100 to V3000 and V3001 and V3001R, and work is very fine, also with different release of software, GREAT!!!