The stabilisation term for the heat transfer with the interface
temperature has been changed to mirror the local heat transfer in the
phase, rather than an effective heat transfer across both phases. This
makes the stabilisation term match the actual temperature-based transfer
terms more accurately. The difference is particularly significant when
the mass transfer rate is high, and cases of this type gain a
significant stability benefit from this change as a result.
Patch contributed by Juho Peltola, VTT.