4G for data, yes.
VoLTE is a very thing though and the device has to meet the configuration and certification required by your ISP to use their voice services.
Mine will not allow me to access their volte services but data works fine.
So, Whatsapp or any other data driven application can be used.
Any advice on how to find one of these in 2024?
Aliexpress
Various outlets
After installing the international firmware, Iām really happy with my Optimus 2. However, Iām missing one feature from the original firmware: the sleep monitoring app. I found it quite useful compared to the exercise apps that were pre-installed. Is there a way to use that app on the international firmware, or is there a good replacement available?
I stalled Sleep as android from the play store. It works well and will upload to google FIT. But it does drain the battery.
Totally agree.
Iāve been on the beta testing list since 2015.
It is extremely good, but as you say, it can eat up your batteryā¦
I got into a routine of slow charging my watch every night.
So the power consumption was no problem.
During the day, itās disabled.
It is definitely one of the accurate solutions and you just need to manage it properly. 
Itās been several months or even years since some people have returned to the site. For those who had an Optimus 2, did you stay on it? And for those who changed, what are you on today?
Finally @pablo11 , Iād be curious to know what kind of watch you have 
Still rocking my O2 as main device. I ditched my phone for main tasks during the day
perfect! i litke it.
i have had a optimus 2 since the beginning and used it every dayā¦no complaints at allā¦i just recently sold it as i bought the vwar core3 and have used it as a daily driver for almost a month now, and can not fault itā¦it works as good as the optimus, has a larger screen and a very good batteryā¦i love the charging as there are no contacts that can get corrodedā¦the only drawback for some could be the 8.1 platform, but i run all my needed apps (whatsapp,facebook,messenger,cam surveillance,all google apps, etc) without problemsā¦
a pity that this watch is not supported here, ti would have been a great additionā¦
i also have a galaxy watch 6 classic LTE, but rarely use itā¦
All of them.
Apart from most of the unsupported ones.
I have some unsupported for testing, but mainly I have MTK and Unisoc watches that are supported here.
I donāt know if I have a favourite, but the Optimus 2 running our FAW firmware is extremely good.
My ideal watch would be the Prime 2 with a 1.8" screen and our FAW firmware.
Unfortunately, itās extremely unlikely to ever happen 
thank you for your sharing
For me the deal would be the optimus 2 in a huawei gt 2 body with nano-sim and with a military grade 
but that too Iām not ready to see.