to be honest it isn't worth it unless you are shelling out for the kit for witness testing which can be in the £0000's. the G59 application process is as easy as peas if you can get the DNO to get it turned around quickly. If a witness test or G59 relay is needed then there are enough experienced folks on here that you could work with to get it all signed off.
if you don't have the volume then dont invest in training for something that probably wont give you the tools to complete the whole process.
if you don't have the volume then dont invest in training for something that probably wont give you the tools to complete the whole process.