Sorry but I think you mistakenly answered :D
LG H860 isn't my device !!
My Phone is LG V20 H990DS (ARE variant_region)
Can I flash one of these firmwares on my phone?
(Oreo has not released for "ARE" Region yet and I want to go for it ...
Hi. I followed this article and I did it (both with SEA and TWN)!
I suggest you to backup all with LG Bridge.
I hope so. Even my phone region is ARE and, following that article, I installed first SEA version, then TWN version and all went well. The only thing to know is that doing so we lost OTA upgrades (we have to do them manually via LG Bridge) and that after booting the phone say an insignificant message of error.