With reference to the lightning strike questions as no Grob that I know of has suffered it is difficult to assess the likely damage except by looking at aircraft with similar construction.
late last year a DA42 encountered a lightning strike over the Channel Islands the strike entered at one wing tip destroying the winglet and exiting from the other wing tip resulting in enough damage to render that winglet BER. The electrical charge damaged the aileron system making it stiff to operate and various areas of structure suffered burn damage that will be expensive to repair but not bad enough to comprimise the structure. However the avionic system continued to operate normally . ( think that one of the engines FADEC controled shut its self down but I can’t conferm this )
I can only congratulate the crew who recovered the aircraft to Alderney airport after what must have been a very distressing flight.
The type of construction of the Grob and DA42 are identical and an identical standard of lightning protection is employed so I would expect it to behave in a similar manor to the DA42 However anyone encountering a lightning strike in the GROB has the additional level of safety that the bang seat offers.