Perhaps it's related to drive configuration? Or a permissions error?

Do you have any suggestions for troubleshooting these? FWIW, I've tried installing on both C (primary SSD) and D (secondary HDD), and I've reformatted and deep cleaned both drives. There are also no errors found on either via disk check.

WRT Procmon: Thanks for this. I haven't tried using it, yet, and I'm interested in seeing what it might tell me.

Steam log files were useless, unfortunately. Zero errors provided. They did, however, track state of Steam's launch. Happy to share if necessary, though.

Steam dump files, unfortunately, do not get created. The steamerrorlogger does not get a chance to run or is unable to catch any errors.