I think he should hand it over to someone else or get someone else involved if he cannot commit particularly if you can still send money, it would be a shame to shut it down as it is such a good project. He has the PCB on easyeda.com open to public download so they are easy to modify and to get manufactured.
Thing is - there is many errors on the PCB along with the software (that someone would have to re-write to get rid of the registration need).
I think it would cost half the price of a Pinsound to get the Tilt Audio up and running IF the PCBs and software worked.