RM50N-GL firmware change

Hello I have a Mikrotik RBM33g router with dual slots for modems and have issues with the number of USB endpoints that it can have of 32. The RM520N-GL uses more then that and will only allow 1 of the modems to work. Mikrotik has suggested to have a firmware change on the modem to reduce the number of USB endpoints it is using.

Hi,

Can i ask you how you connect M.2 slots to the RBM33g? What adapters are you use?

Thanks!