in my experience (before I had a pressing plant), most pressing plants prefer MDC Laquers.
They say, they are much easier to silver then Apollo.
The formula of the MDC laquer surface is for sure different then Apollo/Transco.
We also silvered sucessfully some shank PVC discs, but backround noise from cutting is much higher then laquer discs.
All the steps, preparing, cleaning the laquer etc. are critical, and you never know, what´s happening.
Sometimes you repeat the hole process (cutting, plating, testpressings) and the result is
different, even if all steps are done with the same temperatures, materials etc.
And every plating shop has his own way and formula of preperationl, silvering etc.