The only place where a priority-based queueing (e.g. using DSCP or 802.1q) can work with a radio interface, is on the radio device itself.
When you have a MikroTik device with LTE card, that would theoretically be possible. E.g. the WiFi interfaces do that, when WMM is enabled.
I don't know if the LTE cards can do it. To try, setup a mangle rule like:
/ip firewall mangle
add action=set-priority chain=postrouting new-priority=from-dscp-high-3-bits \
passthrough=yes
That sets the priority at Linux level according to the DSCP field in each packet (assuming that is what you need).
When the LTE device driver knows about priority, it will then send higher-priority packets before lower-priority.
I have no MikroTik LTE device so I cannot try it. But with WiFi it works.