I have a 2012 model VRS TDI and have noticed several times that when you stall the engine it has no power whatsoever for about 1.5 or 2 seconds after restarting it.

For example stalled it coming out of a side road on a hill. Restarted engine and it would not rev at all for about 1.5 seconds so wouldnt move. Is this some sort of safety feature to make sure starter motor is disengaged?

Don't stall it

Type-r did this and the one occasion I've stalled the octy it was the same. I reckon it's just the Ecu resetting/rebooting.

Best to turn off ignition, turn on and wait for the dash lights to go out before restarting. Not always possible in busy traffic though.

several times

Practice makes perfect

Doesn't sound serious to me, but I'd probably mention it during it's next service.

maybe get a DSG next time