For those that want to try new phones, specifically the Aukey B80's, I ordered a pair and they work great, paired up easily with no issues.
However my Nox is one of the original units, about 2 years old.
It has been reported that on newer stock they won't work no matter what you do...probably the same on the 600 models.
Evidently they changed something in the last few years between the original product and what they make now.
When they crossed the line exactly nobody seems to know, can't find any info about that or any way to tell what models will work or won't with other phones.
Of course Minelab won't say anything about this or address it in any way even if they knew where the good model numbers that would work ended and the other model numbers started which would be helpful...but this ain't that kind of company.
They are still telling people to send in units that have that low volume pinpoint issue which is frustrating because we all know this is a glitch they can't, or wont, fix.
Such a hassle for those new owners that do send them in as per Minelab's suggestion and when they get them back find nothing has changed.
As far as I can tell for now the only way to tell if you can pair up to any aftermarket phones is to buy them and try to pair them up on your detector.
If they work, great, if not you just bought some tech you can only use on other products like phones, tablets and smart tv's.