There's either a filter or no filter but let's just look at the results, not what is happening deep in the instrument.
I have Lab values from my iSis using M0 and M2 and I'm measuring Epson's Prem Luster paper which has OBAs. M0 the bstar reads -6.72. M2 it measures 2.5. One tells us something about the OBA's while the other isn't really true because again, it isn't measuring without the UV Cut filter. That is why I wrote: if you use UV Cut, the instrument is blind to the reality of the paper itself.
The basic problem with OBA laden papers is that it will look different depending on the uV content of whatever illuminant you choose to display or show the print. Change it and the print can appear different. There are other issues as well such as metameric shift which is especially a problem for cheap LED and fluorescent lighting but one thing at a time.
Whether profiles using M2 are "true" or not depends on whether the illuminant the paper is viewed under has uV or not. If not, it IS true. The problem is determining whether the light you are viewing the print has uV, and if it only has some, which a lot of regular incandescents do, whether M2, M1, or M0 is the closest match to the level of uV from it.
There is a fairly simple say to determine this with OBA papers.
Measure the Lab value of the white patch on your colorchecker card.
Create a patch in Photoshop and it has to be in Photoshop or some other program that allows Abs. Col. printing. Fill the patch with Lab=(Colorchecker white patch). Then print the patch using each of the three M0, M1, and M2 profiles made for the paper using Absolute Colorimetric. It's easy to print these on the same sheet by positioning them differently across the paper's top and making 3 prints on the same sheet.
Now, cut the patches off so you don't see any surround and have three patches. Good idea to mark the patches with M numbers to keep track.
View these patches against the Colorchecker under the illuminant of interest (home lighting, display lighting, outdoor lighting, etc).
Then just use the Mn Profile that most closely matches.