He likely doesn't knows!
Would be surprised if he knew the difference between a shader and a pile of
He didn't make those shaders and they where not made in 2018.
Even the files are dated 2013.
He is nothing but a thief and a cheat!
The SRPL shaders was made by K_Szczech from SimRacing.PL for Rf1 back a long time ago.
A huge job as he also released tools, emaps and GMT to make use of them.
Later a couple of guys released the SSTR version as K_Szczech wanted people that used his shaders to ask permission for each project and they had to be original projects.
Not sure who changed the structure of the files so they could be used in Gtr2? It could have been Scorpyo who has made a lot of mods using those shaders.
The two sets are identical and if you want to make use of them copy the one set ether SSTR or SSPL into the root folder of GTR2!
None of the shaders he lists will be used only the standard bump, spec and diffuse shaders will and they do not work 100% correct for Gtr2 as they are for rf1.
They will work but are not right.
To use the shaders you need to put the same set of files /folders into the 'hardwareshaders' folder in 3dSimed and select the GMT you want try.