I will argue that these reactor types are not directly comparable.
While a high "alpha" (power/mass) is desirable for both NTRs and reactors for electric power, the limiting factor that causes the most headache for NTR materials is reactor temperature, with Isp proportional to the square root of temperature (not quite proportional, due to hydrogen disassociation).
The Isp in turns ends up having an exponential impact on vehicle mass due to the tyranny of the rocket equation.
In a reactor generating electricity on the other hand, temperature has no impact on Isp when used for electric propulsion.
Temperature does have an impact on thermodynamic efficiency though, as a heat engine with a higher temperature gradient is more efficient (with diminishing returns). This is furthermore made complicated by heat engines in space being run "hot" on the cold end to cut down radiator mass.
So while system mass is a shared goal, it's calculated differently. For a NTR the mass is mostly engine + propellant, while for an electric system it's reactor + heat engine + radiators.
And while peak temperature is a shared goald, it's governed by different physical laws, gas velocity and heat engine efficiency.
Furthermore, a NTR provides high impulse over minutes, while electric systems provides a small impulse over months. Not even the mission profiles are comparable.
It's apples to oranges, so "aggressive" does not carry much meaning.