The LG Xign fabric, at least in its matt version, contains enough optical brighteners that I suspect i1Profiler will need UV-cut data to build a clean profile. The profiles we have made for it all needed software-based optical brightener compensation (OBC) to obtain clean highlights. No experience with the translucent version, but the i1-Pro won't be of much use for it anyway.
We have not used IJ35, but if it behaves similarly to other 3M films (IJ180 and the IJ3650 flavors) the opaque white films contain moderate amounts of brighteners. We only needed to apply serious OBC when the viewing light would be outdoors in direct sun or indoors under standard fluorescents. If these apply to you, go with the UV-Cut instrument. Also, be sure to make different profiles for natural light vs. CWF. There is enough metamerism at play that fluorescents need special treatment.
I know we have printed stuff on various Neschen substrates, but the only one I can find a profile handy for is one of the canvas films. Probably not similar enough to provide useful feedback.
My recommendation would be to get the UV-Cut i1-Pro package if you are planning to use X-Rite's i1Profiler tools. Were you using other software that had software-based brightener compensation the non-cut variant would give superior performance particularly in shadow areas. An alternative is to get the iSis and go through the OBC loops. A painful process, but the results are surprisingly good.