I was trying to figure out a way to print timecode to the ISO and main recorder outputs, as Vmix does not yet offer this.
I came up with this and am also going to expand on it.

Fist up I dont have a tc generator so I went here: https://elteesee.pehrhovey.net/
Made myself a WAV
added it as an input to VMIX and started it, then I set up my audio bussing:

TC file to Master L
scratch mix to Master R
Mic input 1 Bus A L
Mic input 2 Bus A R
Stereo mix of other stuff Bus B

Master recorder MAB and wav (with included channels embedded)
ISO Recorder with audio from Master
Hit record on both ISO and Main
Import files into Resolve, right click update TC from Audio
Create Multicam clip from all the clips using Timecode

Viola! all files on Timeline in the right places
I am going to look into a small FM transmitter I can send the Master stereo to and some cheap FM recievers I can plug into the Camera (DSLR GH4/GH5) mic inputs so it will also work with the backup files on SD cards in the cameras too.

Might work?