This client is new to PT. and at first sent me Hi Hat trks L&R, Bass drum L&R etc. I informed him "there is no need for L&R on everything, so he got it dowh to 19 trks wav files. Now my problem is,, when I import those 19 wav file tracks, they "still" import all those L&R wav file tracks. Any thought how I might advise him? Perhaps "Consolidate tracks"?
Anything that's a stereo track in Pro Tools will import to the HDR as two separate tracks (-L and -R) since the Mackie software uses only mono WAV files for its tracks. (Remember, the Mackie HDR design is practically 20 years old). So if some of his "mono" Pro Tools tracks are actually stereo WAV files with the same thing on both channels, that's where your bloat is coming from. And given that your client is new to Pro Tools, it's likely that he started with a default template with all stereo tracks.
If you know for sure that it's a mono track, you can just import the stereo track, then pick either the -L or -R file from the Regions list to drag into your project.
StereoMonoizer sounds like a clever tool, since it appears to be able to tell you if the two channels are different (stereo) or identical (mono) but if you don't want to spend $49 for it, you can use Audacity for the job. It's free and pretty easy. Under the Track menu, select Stereo Track to Mono, then export the new mono track. I'll warn you now so you won't panic, but when you convert a stereo track to mono in Audacity, the original stereo track disappears and is replaced by a mono track by the same name. So when you export it, be sure to export it with another name like "Snare-MONO.wav" or be sure to export it to another folder than the one where the original track came from. If you're careless or not paying attention, you could overwrite the original track, and that's not a nice thing to do with your client.
As Chuck suggests, do the conversions yourself and keep track of your time.
Oh, and about "consolidate tracks" as you were thinking - this doesn't have anything to do with stereo or mono. It's equivalent to "Render" in HDRese - taking all of his proper punch-ins and alternate takes that he's (hopefully) assembled correctly so that he hears the track the way he wants it to be - and creating a single file for the track-as-heard. That's what you should be starting from when you import things to the HDR. Of course if he's smart enough to render/export stems - like all the drums, or all the background vocals - those are likely to be stereo and the left and right tracks should be kept for your HDR work.