I just tried replacing "C:\ProgramData\photools.com\imatch6\resources\bitmaps\id_plate_photools.com.png" with the path to an identically sized (600x50px) PNG bitmap (black text/white background) to fill the left end of the id plate bar.
When I saved the preferences, and when I restarted iMatch (latest version), the original photools.com bitmaps had been replaced by empty space with the same default colour as the rest of the id plate bar. No sign of my PNG with the back text on white background.
What am I doing wrong or misunderstanding about this customization option?
Hm, this should work. Make sure that the path you use for that bitmap is valid. Any PNG or JPG should do, as long as the XAML markup engine can handle it.
I've made a quick test and it works here (PNG file with transparency):
(https://www.photools.com/community/index.php?action=dlattach;topic=9137.0;attach=21936;image)
O.K., I will retry it later today. I used the Windows 10 "Paint" program to quickly make the PNG bitmap; not sure why it didn't render correctly.