The RC1180HP-RC323 is pin compatible with RC1180-RC232.
Note that the HP variant draw higher current and some of the do-Not-connect pins have different polarity on RC1180HP.
(e.g if you ground a pin marked not-in-use for RC1180, this pin might be used to control PA and will give problem fir RC1180HP.)
There are routing and via on the bottom side of RC11xx, with solder resist covering.
If you have routed signal under module there will only be 2 solder resist film between those line.
If you have bare pad under the module, this is even worse.
Last Update: August 8, 2017