actually, i much prefer the dongle to the alternative - authorizing the hard disk. i can take the dongle from computer to computer. i can replace the hard drive of the computer(s). just be sure to hang onto (and label) the dongles.
to answer your question, yes, you can combine multiple licenses onto a single Syncrosoft USB key. at present, i have Jupiter 8V and Prophet V on the same key as the two Korg Legacy Collections. just wish i could put the Moog Modular and CS-80V licenses onto the Syncrosoft USB key as well!