Thinking about the mounting of the BOV on the intercooler, in theory of course, I came to the following conclusion:

The BOV is intended to alleviate pressure to prevent the surge from a suddenly closed throttle from reaching the compressor.

Placing the BOV close to the compressor, allows more of a surge to build up before the BOV opens up and vents excess pressure.

Assuming the BOV in question can vent the surge quickly enough, the turbo will still be fine.

As long as the turbo is fine, the later opening of the BOV will keep more boost in the charge pipes on quick shifts and act sort of as an anti-lag mechanism.

In theory, of course.

As a side note it seems to me this trick is only necessary if a rather large, laggy turbo is being used. That appears to be the case in these pictures.