A little leehelm under spi is good. In effect this brings you to the safety zone (downwind) when you drop the tiller and do some other very important stuff. Weatherhelm under spi onlu makes bearing down harder and slower, something you don't want under spi.

N4.5 with spi, I don't see why not. Just make it a small one.

Wouter


Wouter Hijink
Formula 16 NED 243 (one-off; homebuild)
The Netherlands