Agreed that XPM mining is a good addition to BTC/LTC mining!  Except for the peopel who bought the cruddiest processors they could find when building their rigs...

Even though only ADD/SUB/MUL are in CUMP, one might be able to use a binomial method (guess/check/converge) to implement DIV without much difficulty though I don't know how well the operation would perform.

There are quite a few factoring algos/sieves on github using cuda, though my cursory glance was showing non-arbitrary precision routines.  I thought floating point arithmetic has no place in integer factorization?!