I've used the SEM for taxonomy work, but only on IMPORTANT plants which
have GREAT significance to botanical study... Echinocactus polycephalus
for example.
I wouldn't bet too much on Nepenthes pollen being useful for taxonomy.
Pollen is usually not taxonomically useful for sub-generic taxa. I would
say flower and seed morphology are likely to be more useful. It would
also be interesting to SEM some of that epidermal pubescence. It isn't
even worth doing though, unless you've got field collected material with
data.
MJC