A radiation-delivery treatment plan includes a first value for a limit as pertains to motion compensation-based adjustment of a radiation-delivery parameter during a first portion of a radiation treatment session as well as a second value for that same limit during a second, different portion of the treatment session. By one approach, the radiation-delivery treatment plan selects between this first and second value as a function of a preselected parameter. Examples of such parameters include, but are not limited to, radiation-beam orientation parameters (such as a gantry-based parameter) and/or any of a variety of external surrogates.