However, reading your post, what comes to mind is whether the effect on whitepoint (which I do not doubt you observed, because I saw the same thing) is the result of UB blocking or glazing color cast or a combination of the two. As I said, even with the non-OBA papers, the Tru-Vue Museum glass added a warm cast (which I believe is the result of the UV coating), while the Tru-Vue AR added a greenish cast (which I believe is from the native color of the glass). I am not sure you controlled for that in your demonstration?
Does it matter what changes the paper white reflectance? In general the effective UV blocking glasses, acrylics and foils all have a color cast related to that function. If that changes the paper white that it makes it less attractive than the OBA free alternatives then there is no gain in using that paper + the UV blocking glass.
In Dutch but graphics tell something, almost all with the qualification: Oordeel = goed (Judged good) show a color cast :http://www.scribd.com/doc/27768335/UV-werende-eigenschappen-van-verschillende-typen-glas-kunststof-en-folies-voor-museale-doeleinden
There is something to be said for another approach that keeps the OBA effect. Not tested but not impossible either. Use one of the protective sprays to seal the surface of the print against gas fading and when framed use glass like Low Iron - Water White that has the least color cast and highest transmission of light. Framing behind glass reduces already the gas fading but the gain with a protective spray may be as effective as using UV blocking glass. Water White glass and OBA papers that withstand oxygen-ozon and light better + a protective coating is the best route then. Papers like that exist, the Low OBA content Canon Heavyweight Satin RC paper tested at Aardenburg shows far less paper white shifting in time even without a protective coating. Some fiber qualities showed improved resistance to paper white shifts when a protective coating was applied.
OBA free papers with a high white reflectance like the Epson Proofing White and framed with Water White glass can go without a protective spray. The paper is not as bright as EEF but has actually a higher white reflectance. Very wide gamut possible on that paper.
With a Solux lamp, samples of more papers and more glass types next to one another it should be possible to get that satisfying choice where the desired print quality is kept in time too.
met vriendelijke groeten, Ernst
330+ paper white spectral plots:http://www.pigment-print.com/spectralplots/spectrumviz_1.htm