I'd rather buy something with a micro USB at this point, than something that doesn't do proper USB PD. At least you definitely know that you need a different cable.
* https://www.tindie.com/products/cuvoodoo/usb-c-cable-tester/
I mounted it in a little clear case back to back with the microUSB tester board. The battery should effectively last for a decade. There are multiple other similar boards on tindie for comparable prices. I picked based on being able to consolidate shipping price for multiple units; make sure to check where it ships from and how much if you only plan on getting one board.
Searching for "usb c cable tester" on every major search engine pretty much solely returns port testers despite "cable tester" being in quotes. The product category must be pretty stark (and my god do search engines suck now).
I'm also pondering a way to mark my cables with the results of this thing. Color bands (like resitors) with nail polish or something?
* https://www.tindie.com/products/petl/usb-c-cable-tester-c2c-...
but I have no experience with it, so I can't recommend it personally.
You should ask on the /r/usbchardware subreddit. They are generally a friendly bunch and have experience with these exact use-cases.
EDIT: re:color code marking:
As opposed to the one GP linked which just shows which lanes are connected (i.e. if it's only USB2 or not, it has an e-marker or not), this one is fully featured: it reads the actual contents of the E-marker, revealing if the cable supports 100W, Thunderbolt, etc. It even sometimes shows the chipset brand name in the cable!
It can also check Qualcomm QC and USB-PD chargers to see what voltages/amperages they support.
Some "screenshots" of it in use https://bitbang.social/@kalleboo/109391700632886806
(I can read Japanese Kanji though, which along with the screenshots which are pretty clear on the feature set gave me the confidence this is the right thing)