How to add multiple Huawei 4G dongle dynamically as Plug and Play ?

[gaamaaresosa]

I use Raspberry Pi 4 as OMR
I need to plug 4 to 6 numbers of Huawei 4G (SIM) usb dongles blindly via powered USB hub.
At live streaming video location, I need to decide how many SIM dongles needed for reasonaly bandwidth over there. So I can't preplan before and I can't fiddle OMR at location.

1. How to configure OMR in advance to auto detect the Huawei 4G (SIM) usb dongles ?
   I see only 2 (wan1,wan2) and how to add more ?

2. Which is the proper way to add new interface out of below 3 methods ?
   Network > Interface
   Network > Devices
   OMR > Settings Wizard

3. Can we add extra interface without connecting actual device and keep ready for dynamic
   auto detection ?
   If yes how ?

I see no proper video tutorial to add interface on OMR, please help