There's not too many passenger carrying companies that'll let you fly around without paying pax for an hour or 2 after maintenance is completed. Once round the pattern or a repo to pick up pax is all I've ever been approved to do on Ops check flights.
Agree 100% Unless there is a minimum amount of time specified in the MX manual, at which point I will fly that amount of time. With a decent SMS program and quality maintenance department I see no reason to do any more.
My mechanics always fly with me for the mx test flight also----if they refuse to go, (which has never happened btw), then I will not fly it.