You have a rare MCU version, I couldn't find MTCE_AW anywhere. You don't need to update the MCU, 3.75 is a fairly new update. Crossing MCU manufacturers is not recommended. You can also update the firmware(rom) from other manufacturers, but no one can guarantee that the Z-link will work. You have to try it yourself. First, try contacting the vendor to see if they have firmware and MCU updates. Z-link can be updated separately but you have to ROOT but it doesn't work very well see the thread below. If everything works for you, leave it as it is, you may cause yourself more problems than now, there have already been many cases where updates have been bricked. Especially Dasaita(HA) has white screen issues after firmware update. It can be fixed, but why add more work.Please read the MTCD threads thoroughly first.
Z-link:
I just backup the Apk Zlink app from my Dasaita Max 6 PX6. Someone need it can download and use :) Download here : Zlink 4.0.37 https://mega.nz/file/aURAgTTB#n8T2Q9T-1cNKTRcNAKlm0VD27G5hpzdWUh0L0z94kPs
forum.xda-developers.com
Here you will find the firmware of all px6 android 10 manufacturers, including HCT, there are attached screens that you can use to identify your ROM:
Найдётся всё
disk.yandex.ru