Disabling LTE interface does not necessarily mean the LTE device will be powered down. So no SIM reset.
USB reset will effectively power down the device connected to the USB bus for the time specified.
And the block diagram of LTAP LE6 shows indeed that pci modem is connected to USB bus.
A very brief search on USB reset:
http://forum.mikrotik.com/t/script-for-auto-reboot-reset-usb-power-reset/154590/1