It'll be interesting to see what is in that filter - I've cut open engine oil filters before but have never had, let alone dissected, an external transmission fluid filter.
My last Landrovers (Discovery 4.0 V8s) had built in gearbox filters, which as you say were hardly more than a very fine mesh. They certainly collected a lot of fine metallic particles, but I'd be happier if even smaller particles were collected as well - there was always a nasty grey metallic sludge in the bottom of the sump whenever I changed the filter. Ideally the filter should have picked all that up and held it within the filter.
We come here for enjoyment? Surely not, I hear voices that insist I come here and spout drivel
Speaking on which, I'll have a look for an aux cooler the next time I'm under the bonnet. You may be right in that the 'R' has them fitted as standard, just that I don't recall seeing one. But my post covid memory is far far worse than my pre covid memory - and it was never very good then