I have, and it's nice, but I like installing Bootstrap via NPM/some other package manager so I can track new versions and include its JS components, and I wish these shipped as a diff or something so I could install stock Bootstrap and pull in the changes. I'm unsure what would happen if I used NPM to install stock Bootstrap, then included the modified stylesheet after. If I could see, I'd just try it myself and see what happened. Thanks for reminding me of these themes!