I have been looking at RouterBOARD for a custom solution. Two LTE interfaces for two different types of modems is important, so is wireless. Wondering why there is no RouterBOARD that has a wifi chip onboard and multiple miniPCIe slots. I understand this board replaced RB953 and RB433. RB953 had wireless plus 2 miniPCIe slots and RB433 had 3 miniPCIe slots, one of which could be used for wireless. On this board, you only have 2, there doesn't seem to be any option to have wireless+2 modems.

A little surprised that a new board that replaced others has less options to it. Anyone knows if there is a plan for an enhanced version of this board, either wireless by default or have more than two miniPCIe?

You could use a USB LTE modem to free a miniPCIe port for wireless. Many LTE modems have USB carrier boards with SIM card slots available.
Alternatively you could use an integrated wireless device connected to an Ethernet port on the RBM33G. That brings up a point on this board and it's lack of POE out together with no temperature and voltage sensors.

LtAP (not mini) has Wi-Fi (built-in) and 2 miniPCIe.

Regards.