I live in a perceptional backwaters on the trailing edge of trendy daily calendars.

Aren't normalise and the other one there to adjust audio clips that are not perfect, rather than the whole mix?

Normalize will analyze the mix and automatically do a one-time adjustment to the render volume such that the highest peak (or RMS using RMS) level will be at 0dBFS. I use peak... perhaps RMS would be used in conjunction with analog gear but I can't see how RMS normalize could work with digital source material.

I've used it in Wavelab. RMS Normalize can be used to render a set of matched loudness clips such for an album of relatively equal loudness songs. It can be useful at least as a reference. You may want to tweak those song levels afterwards.

The last tune I did was pushing Tracktion 4050 and my system, windows XP w/ sp3, to about 70% on the CPU meter. Around 17 tracks and a ton of plugs. CSR and Valhalla reverbs, sends on everything. Reverbs and the receives are prefader. I think I tried postfader as well.

It seems to me as though the reverbs did not render. At least they are not audible on the render but very noticeable from the Tracktion mix.

Any ideas on something I might have overlooked... anyone else having similar?

I was having some rendering problems, too, but there's probably not much point reporting it until the new build is out and we can test it.

For the record, though, any render with a non-Tracktion plugin as a send/return was very odd sounding. Kind of like a bad, stuttering delay.

I did not have this symptom... just seems the the reverbs have gone AWOL.

I'm with you - hang tight for the next release.

I would expect reverb on tracks to get buried by the release portions
of sounds, and ambient backrounds, on 17 busy tracks. To the extent that
reverb is the tailing absence of sound, maybe there are few quiet passages
where reverb would be stand out in the mix. Maybe try with only the core tracks,
and use only one reverb, in case there is some sort of cancellation occuring?
Cheers

Good thinking however - In the intro I have a female voice with gobs of reverb. I did it partly because I liked it and also because I wanted to see if it went missing on the render. I could not hear it on the render with perhaps one or two simple tracks simultaneously.