ZBT WG1608 update to 19

I'm about to order ZBT-WG1608 with has a MT7721 CPU it only run old 17.01 but they say they reprogrammed it

... our device can support openwrt firmware. But it's not opensource firmware. they are reprogrammed buy our R&D team. And our openwrt firmware version is 17.01 near to 17.01.2

Can I update it to v.19?

It might be easily ported, but you're buying at your own risk.

ok i have two options to update to OpenWRT

try the WG3526 or the GoldenOrb from ROOter.