Ricky be interested to see whos calcs you use for the hybrid system your using when you mix.Lets hope alls well with your scaffolds because when you get a failure the HSE will want to see the hybrid scaffold method statement,design and calcs and thats before insurances are involved.Plettac is not the same as Layher different loadings,quality,dimensions,etc.
It might fit together but thats all.Guessing your using either Plettacs or layhers calcs and getting away with it as ive not seen calcs for these two mixed.
If you know any designers that mix the 2 knowingly,let me know !!!