I've attempted to determine the solving time per loop as a function of the simulation time, in an attempt to identify any trends in the solving time for a constantly dynamic load.
The following is a plot of the solving time per loop as a function of the simulation time for a load which is constantly dynamic (sinusoidal in time, in this particular run).
The mesh size is normal (default in COMSOL) with heat fluxes from both the beam and the ring heater (as in the real case).
It is difficult to identify any particular behavior or trend due to the large amount of "noise" other than a trivial general increase after ~4 s. Mesh quality does not appear to influence solving time per loop significantly.
Work must be done to reduce the total solving time for the simulation, which in this case amounted to 18 and a half minutes (1.1109e+03 seconds).