Viability of a multi-manufacturer, 100cc TaG Class?

Mixing the motors was at least trialled for a while in Cali:
@dagee2 talks about it here in this topic:

Re-reading this got me thinking… and it’s a rhetorical question IMO.

In a world where well supported, quality engine packages with established rulesets exist…
How do “local” motors add value to the racer?