In my scenario I do swap of SIM Slot via SMS… but this run script who do:
change for lte1 interface to proper APN Profile and do some other changes like set IMEI, set TTL, set MSS etc..
When I want do change of SIM slot I always go to system > scripts and RUN script ChangeSIM.
My script works for RouterOS7, you probably works with stable one, but example is here
http://forum.mikrotik.com/t/r11e-lte-configuration-help/138222/8
I not use the “passthrough” but when I test it I use differ VLANs for each simcard. You can use easier way and script that in scenario… when change sim then sim-opposite disable passthrough apn profile and activate passthrough interface in new sim apn profile. Two lines more in each site of script.