Crowdfunding the creation of the next version of LFGSS

I don't think that's right - HMRC imply otherwise.

However, there's also some stuff about holding shares for 3 years, and only being able to claim relief once the company has been trading for 4 months (or has spent 70% of the funds raised) ... not sure how that all works in practice.
There are a few rules about qualifying for the scheme. After set up HMRC look at it all and if it is OK they issue certificates that allow the 50% offset against tax. This could take a few months, pushing the tax benefit into next year not this.
Microcosm has to keep to the rules for 3 years and we have to keep the shares for 3 years otherwise the deal collapses and HRMC could ask for some/all of the tax benefit to be returned - or add it to your next tax bill.