The only thing he can do , i did it to with a simjet 1200 , is take a piece of sand paper 600 or 800 , and make the small nicks nice and round again.

I have a lot of experiance with dirt in turbines , and when i see this little damages , i grind them with very fine paper away , because it can be the beginning of a real brake point.
So if every blade is nicely round , no sharp or damaged ends , then i shoud be oke.
I even had a compressor wheel from garret 54mm ,and i let it fall by mistake on a hard surface.
One blade was bent , but it put it in ,and it still runs , and its has run more then 70 hours now, so be afraid , polish the nicks ,and no problem.

Best regards,

Martin.