That sounds really interesting, there is an oval series in the UK called GP Midgets, not sure whether the rules are still the same, but they had a minimum wheelbase of 82” (2.082m), the class used to be real mix, some front engine, some mid engine, a-series, Ford & VW power units.
Using a motorbike engine was not allowed. I think that given the even shorter wheelbase of your intended class, I would be inclined to offset the driver and mount the engine longitudinally next to the driver (a bit like an old Mallock-style ‘clubman’s’ race-car); this would let you fit either a reverse gear or fit an electric motor & battery for reverse, you would also be able to sit fairly well back.
Does the 45mm roll-hoop allow you into track-days for testing?
I’d be really interested to see the full construction rules for the series and see what I could come up with!!
Perspective - Understanding that sometimes the truths we cling to depend greatly on our own point of view.