FAQ: Watermark Premiere Pro Proxy Files
Premiere Pro v. 22.5 has built-in watermark capabilities for proxies, so you no longer have to burn in a watermark manually. There are also new Proxy badges in the Project panel and timeline enable you to easily distinguish between proxy and source media while editing. For info on how to do this, see the Ingest and Proxy Workflow article in the User Guide.

If you would like to add your own custom proxy badge, see the following instructions.
"By adding a PNG file I created to the proxy export settings in Adobe Media Encoder, all my proxy files now include a transparent "Adobe Proxy" logo on the final rendered video. This technique makes telling the difference between native and proxy incredibly fast and easy."
-Matt Johnson
Here's a free watermark for your Adobe Premiere Pro CC Proxy Files from Matt Johnson.
I use this all the time. The article also shows you how to create a new proxy preset with the watermark. Though the article is from 2016, the technique for adding a watermark to your proxies remains the same.
Let us know if you need help or have questions.
Kevin

