Most of Purolite MB400 which we buy for window cleaning is regenerated, when it is regenerated then 60c is max. When it is pure virgin the 100c is max.
Best have a word with the manufacturing company direct to find out the true impact.
When I spoke to Thermax and I was worrying about temp etc.. they informed me if it reaches a certain temp then the resin cracks. The same can be said about freezing temp when you leave your di vessle in the van, this has an impact on your resin as well.