most superchargers have a pop off valve otherwise the backfire can turn from deflagration (a quick but controlled burn, just like normal engine combustion, and even in a firearm) - as pressures spike, into a full strength 'detonation' (a much more rapid and violent burn that will do significant damage)

FWIW there's been similar options (albeit with lysholm type compressors) to supercharge the mini a-series and bmc b series engines - done by 'link automotive' and 'hi performance products' (who are in the same street - thornton crescent in mitcham - or were the last time I looked)

They were around $5-6000 in the late 90's - no idea their price now. That was a full kit - charger, pulleys/tensioner/belt, intake manifold and SU carb (hif type iirc)