Ok, so I've checked the archives, I've researched online, now I'm looking
for imperial information.

As it relates to body work.  I've seen numerous posts on various composite
finishing sites about using some of the newer polyester based fillers.  A
couple of examples.  Evercoat makes a line of "RAGE" fillers that are
polyester based.  The one most discussed is Rage or Rage Xtreme.  The later
claims to be less at creating pinholes.

In the past, most have suggested that for *light* leveling, and filling when
doing body work, that you should *never* use one of these fillers.  However,
I am curious.  It seems that the composite body shops for cars use them,
also they are heavily used in metal body repair.  So, why are they so bad
and has the technology changed enough that these would be ok to use and they
won't have the shrink, crack, etc issues of the older generation?  I'm not
talking about "contouring issues", I'm mostly talking about thin leveling
issues that you're trying to correct.

The discussion on primers was a good one, so I figure, I'll try it around
fillers?

Thanks in advance,
Alan