My strive for a "D50 simulator" should not be taken too literally, the purpose I have is a smooth spectrum, no significant broad peaks or dips, no significant spikes, with an overall distribution similar to D50. For camera profiling there's no real value in exactly matching D50 as D50 doesn't really exist in nature either. The purpose of this is to have an alternative to going outside using actual daylight. Shooting glossy targets with minimized glare is a lot easier to do with this type of light source than using real daylight.
Now I'm pushing it to 5500K to get a little bit more spacing from 2850K in a dual-illuminant scenario.
Compared to a 3000K halogen lamp with an 80B filter all indications I get is that the overdriven Solux makes a better job. I'm sure though that Liu labs lamp is even better, but I doubt it will present any significant gain, except if we want to get closer to 6500K which the Solux can't do.
It's far from a practical setup, I have only one lamp, flatfield correction is required, temperature stabilization is required, it's preferable to measure it. I wouldn't use this for copy work or anything like that, but to shoot a target with flatfield-capable software it seems to be a good setup.
The value of actually measuring the spectrum is there when we want to make a DNG profile that can do precise whitepoint estimation, otherwise it's not that important when we make a generic "daylight" profile.