You are correct. I just came back here to correct my error. It's been a while since I converted my a/c. The loaner manifold gages would not depress the valves far enough on my lines. Could be due to the R134 adapters I had to install. But the HF gages I bought did work. The equipment in the pic is what I used.
If you took your car to a reputable shop to have it charged, they would let you know that it won't hold a vacuum if that's the case(probably still bill you). They wouldn't just shoot refrigerant and hope for the best(some would do this). But yea, it would turn into a money pit paying someone to fix any issues. I installed a new compressor and expansion valve. It wasn't that big of a job. Paying someone to figure out if you have a leak doesn't make any sense to me.
