I haven't heard of Chlumský or MSDF before, but I think a lot of people have been aware of the technique before he published his paper, thanks to Valve's TF2 text rendering paper:

https://web.archive.org/web/20120505013814/https://www.valve...

The pdf details only simple SDF, but in the closing paragraphs, it mentions the weakness of the technique and mentions how it can be solved with multiple SDFs, but the exact technique wasn't showcased.

Which led to people trying to reverse engineering it, and making their implementation, for years (it's Valve after all). Including me. Not sure if what I came up with was exactly MSDF, but certainly there are a lot of implementations out there.