Yes, as I said in a PM, I'm familiar with that discussion on AM... Perhaps I am stating the obvious, but typically, double pass auto collimation (DPAC) and interferometry don't require any sort of interference filter to isolate a specific color. The star test of an achromat is the exception and to do properly requires Wratten #11 yellow-green, Wratten # 56 light green and Wratten # 58 green in a stacked and single configurations.
If the scope is as good as Ed Ting, you and others say, I think we all may be pleasantly surprised at how well it tests at the wavelength in which it was designed.
This has been an informative thread, thank you for starting it.
On the contrary, I'd expect the opposite but I wouldn't limit myself to an optical evaluation. I'd evaluate the mechanical functions first, specific to the collimation of the elements within the tube, meaning the alignment of the fixed cell, focuser induced collimation errors, stray light suppression by baffling and an evaluation under load, ie with focuser induced errors associated with heavy eyepieces or cameras. While I'd expect the collimation issues to be obvious under the optical testing as well, I'd prefer to have a more thorough optical mechanical assessment first.
I'd agree that we'd all be pleasantly surprised if the objective performs well under testing but that's not what I'm expecting. I do expect to have a thorough report detailing various defects evident during testing. I think that's axiomatic and I expect it to conform to the expectations of the tester.
That said, I'm not particularly concerned about a sample size of one so whatever the findings may be, I'd be skeptical that they can be generalized to an entire production line of mass produced telescopes.
Further, as I've previously stated, I doubt most observers can discern the difference between a 1/4 wave and 1/3 or so in the 120mm F5 richfield unit and I'd bear in mind at all times that the operating parameters for which the scope is designed and marketed by the seller should be prioritized above that realized in an optical bench test...