2 ways to address your concerns. Buy an OBDII (about $40) and download OBD Fusion ($4.99) onto your smart phone then go to this thread ---- “New” 2018 2500 Ram. One of the members here has created a user define PID that allows you to anticipate when the next regen will occur. If your DPF is around 98% you will know that a regen will start shortly and you can plan accordingly. I suspect that RPM is the important factor not vehicle speed so if you are four wheeling go in 4 LO and/or manually adjust the transmission gear to keep the RPMs up. My active gens last about 15-20 mins.
That doesn't really address my concern. It may give me better awareness of the status of the DPF, but if I'm driving in 4wd low in a forestry road and the DPF says it needs me to drive at highway speeds to facilitate a regeneration, what am I supposed to do?