The screen is displayed the whole time - no "black out".
When the "interception checker" is working - the current checked line is highlighted... so not all results are IMMEDIATELY displayed. But you actually can SEE the worker working - which I find nice!
A check of ALL lines in the interrupt takes about 6 seconds - sounds "long" but I find it better playable - since you can immediately continue playing... just when you have finished - you need to await the last update - to get the "YOU WIN".
I did not tweak any "vector performance" - and I am afraid the thing updates in over 30000 cycles. So to be on the save side, I set the WaitRecal to 50000 cycles. With a good overlay the flicker is barely visible!
If you play it in Vide...
a) you need an analog joystick
b) you must disable "Try autosync" in the configuration (due to the different timing parameters)