That will need something extra special in the transmission.
Either some extreme means of reducing shock loads &/or a gearbox manufactured specifically to deal with the torque transmission. The clutches available are no longer the weakest link & actually excaperate the issue. Slipping clutches actually helped absorb shock loads. IMO you can forget about shiny red springs (no pun intended!) helping on the front sprocket, although, with research, there could be an ultimate solution to the relatively crude OEM design....
I'd even be looking toward a special three speed gearbox as one means of increasinging the contact area. Teeth shear @ their root. Even OEM principles of 3/8" pitch duplex chain may be on the limit, so I'd be thinking triplex.
i wouldn't want to be launching a sprinter with so much power (the torque for which will inevitably be high. if not now, then ' a later date) with the uncertainty that the gearbox will grenade.
Whilst I'm on my soapbox

I reckon wheelspin, to an extent, will help so we might get to see wheelie bars on a Lambretta sprinter. That said, how much 'Lambretta'' is this type of engine?
That all said, a fascinating prospect, even if opinions might vary upon the 'spirit of what of the OEM Lambretta remains' when all is considered.