Are they any good? like the ones from these guys ARMTECH Motorsport Electronics

I was wondering if this would be a halfway house between dumvalves and full blown antilag for reducing turbo lag? My only concern is what happend to all of the fuel durring and after the gear change? or is the time spent in this "no ignition and over fueling" mode negligable?

 

IIRC from when I used to run a FTG module when quarter miling my old Clio, you'd get a pop or a bang from the exhaust when flat shifting but not much more than that, and tbh on the dragstrip my changes were so brutal and fast that you barely even got a pop. On the road you'd get them more.