Familial PD cause

If healthy LRRK2 promotes chaperone mediated autophagy then screening for inhibiitors of LRRK2 isn't going to be very useful in finding molecules to block neuron death.
Bartobob, where did you read that LRRK2 promotes autophagy ? I only read that bad LRRK2 disrupts autophagy process. So if an LRRK2 inhibitor can inhibit the bad LRRK2, I see potential.
You are right. It doesn't follow that if mutant LRRK2 disrupts autophagy that healthy LRRK2 promotes it. There is independent evidence elsewhere however that the normal function of LRRK2 is to regulate autophagy.