For most alloys, the electrical and thermal conductivities are proportional.
This relation is quantified by the Wiedemann–Franz law, which states that the ratio of the electronic contribution of the thermal conductivity (κ) to the electrical conductivity (σ) of a metal is proportional to the temperature (T).
There are some exceptions, however, where this relation does not hold (I recently read a relevant article for nanomaterials, which I'll try to find and post as a reference if you are interested).
So with respect to the thermal conductivity and whether it's low/high, there is usually not much freedom. It is mainly a property of the alloy.
Regarding whether low thermal conductivity is desirable, I would be surprised if that were true. However, I would expect that high temperature applications require more dimensional stability (corresponding to a lower thermal expansion coefficient). So it might be that while obtaining the lower coefficient of expansion, the thermal conductivity is also lowered.
For example, in some cases the thermal conductivity and expansion coefficient of alloys don't always follow one another (see below for a CuCrZr alloy - I couldn't find data on Ni-Cr),
Below is the thermal expansion coefficient for Ni-Cr alloys and you see that the behaviour can change quite a lot in some cases.
Finally, Electrical conductivity can be influenced by high level of cold deformation (e.g. work hardening) and small grain size. For example small grain size decrease the electrical conductivity moderately. However, work hardening and thermal processes that results in small grain size are commonly used to increase the strength of a material. That increase in strength is also welcomed for turbine applications.