He's got a point. Software like EOS Utility is typical Canon, the GUI looks terrific but functionality is sadly underdeveloped. BreezeBrowser Remote Pro is a brilliantly featured tethering program, provided you have a PC.
The Mac version lacks many of the useful features of the PC version...so much so that even EOS Utility is preferable.
I have EOS Utility on my MBP and it's set up to feed directly into PhotoMechanic. Kind of OK, but EOS Utility is alarmingly unstable on Mac, crashing often.
Once you have PM5 & the catalog function bedded down, why not turn your programming skills to a tethered function for PM? Pitch it as a paid add-on. I'd pay $100 in a heartbeat. Who wouldn't?
Paul Wright