after a discussion with a friend who is a long-time corporate pilot/ATP/CFII, I am reversing my position on this, and here is why.
he said many airports that don't have radar coverage low enough to descend you below the MVA to the glideslope/path intercept altitude. so they give you a clearance to maintain the MVA altitude "until established" so that you will intercept the final approach course inside an intermediate fix aligned with the runway. Once you turn inbound, you are actually on an intermediate segment (note the thick black line), which is a published segment of the approach and you can then descend in protected airspace to the altitude at the FAF.
in the case of TCL RNAV RWY 4, we know from the ADS-B track that @0TreeLemur intercepted the final approach course at least 8nm from the threshold at 4000, which puts him inside CAPOG (11.1nm), heading 041 (note on the chart that this is specifically the final approach course) for BUPGY, and he can therefore descend in compliance with 91.175(i) to cross at 1800, and capture the glidepath
The reason they don't clear you to the IF is because you're talking to TRACON and getting vectors to final, which means they send you to the FAF. If you want to fly the full approach, you have to ask for it, in which case you'd have to go to an IAF, not CAPGY because CAPGY's crossing altitude is below the MVA
So, in actuality, @0TreeLemur had at least 3 miles from when he intercepted the final approach course until BUPGY to lose 2200 ft. Still not a great descent rate to capture the glide path, but certainly better.
here's another link to the plate: