This Hanna blog raises a good point, based on TDS Meters commonly being accurate +/- 2% (or 20 ppm). Take a look at your meter accuracy & see for yourself.
Just to be sure of the purity, I would use the DI stage(s). It won’t hurt & if the water is really zero, they should last forever
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I agree with @ichthyoid TDS meters are not 100% accurate, Running the DI is just peace of mind that your are getting 0TDS
0 after membrane? I kind of doubt it. I would use the DI too ( both the different DI) just to be safe. I believed there are 2 different DI resins for the last stage/s