This is the same profile that we had used when we were using onyx. With onyx it worked perfect but now that we are using flexi it is not as good with mainly the yellow. I don't know too much about all of the settings on flexi but I will check out some things and see if I can figure out any of that. I have never really modified a profile specifically for the vinyl. We have always just used the recommended profiles and have never had any problems with them until now with this material.
You need to narrow down the source of the issue, as there are two basic possibilities:
1) You are experiencing cross-contamination in the K-Y printhead(s)
2) Your media profile is creating the 'smudge dots' in the yellow.
The good news is that it is easy to figure out which is responsible by doing the following:
a) Run a Printhead Test Print (from the printer's control panel: Ink Menu > Image quality maintenance > Clean Printheads > Test Print. If there is cross contamination happening in the printhead, you will see it in this test. The solution in this case is to clean or replace the affected head(s).
b) In there is no cross contamination happening (as I suspect might be the case), take the attached PDF file that contains filled strips of 100% CMYK, and print it with all color corrections/ color management turned OFF in the RIP. Doing this will pass through the straight CMYK values, without corrections or adjustments. You should see no scum dots in any of the colors if you do this. As I recall, Flexi also offers a 'pure hues' function that may perform a similar function.
By the way, with the Latex 260 printer, your comment about using the same profile in Flexi that was used in Onyx is not possible. It would be possible in the Latex 300 series (OMS files are RIP agnostic), but not the 200 series machines.