One more small point (accidental pun) on anything above 12 points to the inch:
I’m not sure there is any benefit to filing cross cut?  I just go to a simple
rip pattern for the small teeth because even with magnification I ended up
missing the tooth space I intended and screwed it all up.  I had intended to
just file all the teeth at 90 degrees first (ie rip pattern) just  to start over
with  ordinary rip pattern teeth before filing facets into it to restore  it
back to the ‘factory’ crosscut pattern.  Then  I cross cut through a couple of
bits of scrap just to see how it cut before doing anything else to it (so I’d
have a baseline) and then realized, why the hell would I even want to?  It
worked just fine, since I was only using it to cut the shoulders of tenons
anyways.  So from then on, all backsaws 12 points or greater were filed rip
pattern.  On the bigger teeth, cross cut filing makes a big difference.  On
little teeth, I can’t feel or see any practical difference in performance, and
it’s a lot simpler to sharpen. Ten minutes and you’re done, even less on a
gent’s saw.  This follows the first of the basic principles of all sharpening:
It has to be a process that is fast, easy, and efficient, otherwise you won’t do
it when you should. As soon as you feel the tool isn’t cutting as sweet as it
should, you can sharpen up in a few minutes and get back to good condition
without making a big deal out of it and ruining your work flow.
  And it you are doing miniatures like ScottG, get a $10 Zona saw with small
teeth (I think its 24 tpi or something); (they don’t call them razor saws for
nothing- I sliced through the skin of my knuckle in a moment of carelessness
years ago).  They really cut well, and the form factor is excellent, especially
for model size projects (Jewellery boxes or doll house furniture and whatever)
or if you are using really thin stock.  Desktop dovetailed boxes made with 3/16
or  !/4” thick stock look delicate but are very strong.
Cheers
Claudio