Just a thought, maybe your tds meter is faulty, after resin sould be 000, try another one just to rule it out.
You could try a dozen TDS meters and get a different reading from each one. If you're that bothered get some calibration fluid and check your meter.
This obsession with "000" makes me laugh, there's no law says you have to have 000 - it's just a convenient way to describe how pure the water is, it isn't a magic formula for cleaning windows. At some stage of purity (it could be anything from 000ppm up to 015 or even 020) there isn't enough contamination in the water to precipitate out on the glass. That's all you need. Clean windows produced using 020ppm are just as clean as clean windows using 000ppm.
Stop worrying about it, experiment with your own windows - you'll know if your water is pure enough for the job or not.
We don't start worrying until our reading is 015, then we think about using resin, otherwise it's just straight from the RO.