I think what I am reading here is that there are no 'Native' 6/8 time signatures. There are just workarounds that 'resemble' or 'simulate' the 6/8 requirements, albeit many times not too perfectly.

Doubling tempos is generally undesirable, as some instruments just become too busy, as John F pointed out. That's been my experience too.

BIAB & RB2025 Win.(Audiophile), Sonar Platinum, Cakewalk by Bandlab, Izotope Prod.Bundle, Roland RD-1000, Synthogy Ivory, Kontakt, Focusrite 18i20, KetronSD2, NS40M Monitors, Pioneer Active Monitors, AKG K271 Studio H'phones