It’s only been 16 weeks since V2 tanks began shipping, so you might be hard-pressed to find anyone yet who’s surpassed the recommended limits (at least by much).
Their recommendation for Tough 2000, Elastic Resin, Rigid Resin and Grey Pro is “10 weeks exposed to resin or 3 liters of printed resin, whichever occurs first”. And “35 weeks exposed to resin or 5 liters of printed resin, whichever occurs first” for the other resins.