All I would care about is that the standard of instructing the OP provides is better than the majority of FI(R)'s coming out of the factorys
With the change to EASA there is no requirement for a CPL to earn money instructor the OP is doing nothing wrong.
And to be honest I would be employing these PPL instructors before CPL FI hour builders. There is a small hope in my head that these instrutors may actually turn the tide with the spiral of dropping standards.
There will always be a space for CPL hour building FI's basically because they are the only ones that will do all the ****e in the school.