I found the Nighthawk M1 has a new Hong Kong version, which supports more LTE frequency bands than Telstra version Nighthawk M1. See details:
-- Hong Kong Version Nighthawk M1: Supports LTE Band 1/3/7/8/20/28/29/30/38/40/41
-- Telstra Nighthawk M1: Supports LTE Band 1/3/7/8/28
(Sourcing from https://www.4gltemall.com/netgear-nighthawk-m1-mr1100.html )
My question is whether the HK version Nighthawk M1 would work well with Optus 4G SIM?
More than likely but why pay all that extra coin.. Assuming you purchase from there I see there’s an extra $60 on top of price for the HK ver.