I am working with some guys on a MarlinKimbra version with full support for 8bit laser engraving.
The firmware is constantly being worked on and upgraded - although with the main aim of using it for a dedicated laser machine.
However once is up and running the plan is to move it into the main branch along with other requested features.
You can check my threads in the laser secetion for updates.
The problem with a mixed mode system is that you not only need totally different settings for printing and lasering but also that the hardware involved needs to be addressed somehow.
One simple workaround with Kimbra could be to setup the laser like usual with the first extruder but to simply add a switch to shut off the laser power supply when printing.
Of course you would still face the issue of the heavier mass with the dremel and the need for differen speed profiles.
But if in doubt those can set in the gcode when the EEPROM support is enabled.
As an alternative you could try to set the printing stuff up on the second extruder if the first approach does not work, but then you would be limited to just 2 extruders, not sure if that is enough for you....