IIRC they didn’t take ANY valve float and they were sensitive to spring pressure falling below spec.
And IIRC, there were some issues later on with the ceramic coming off the lifter and when that happens...
And IIRC Schubeck was working on a ceramic (or some other materiel like that) roller lifter that didn’t have a wheel, but the lifter had a pretty big radius on it because you could design around the lifter bore size and wheel diameter. IIRC the equivalent convention wheel diameter would have to be something like 2 inches or something wild like that.
Don’t know what ever happened to that system and how far it was actually developed but it would be interesting to see if it could be developed further.