I was thinking too that I may re-bore the taper inward a bit more so the pulley sits a few mm inward at idle, thus making it so when it's fully variated it's only sitting a few mm outward; make the mid-range the 'straight' as that's where one likely spends most of their time.
I think I'll give it a try with a BX40 rather than my stock belt as I'd hate to destroy it on an experiment like this.