Employability in flight test is a complex beast - flying experience, technical qualifications, track record, flight test training, practical experience, and most of all whether they actually need somebody, all are major players.
Within that, it's hard to see that qualification being a bad thing - 13 weeks intensive flight test training at the world's best known TPS. It's certainly likely to carry some weight, but probably less than having a lot of real-world FT experience.
On the other hand, looking at what's shown there, I suspect it may be less cheap than doing your ATPL all over again. I should ask about the price before getting too enthusiastic.
G