Kveik doesn't finish fast at those temps. The thing about Kveik isn't really that it's faster, but that it allows you to ferment at higher temps without off flavours. If you'd pitch let's say US05 at 35 degrees it would most definitely finish in about 3 days also, the difference is that the beer would taste fenolic and probably a lot of other bad things and it would give you a baaaad headache. Kveik doesn't. Pitch it in hot wort, ca 35-40 degrees. Wrap it well in your hottest room and let it work. Use it right and you'll love it.