In my opinion 000 TDS is overrated.
Go out and clean some windows with less then 000 TDS. Works just fine. No spotting whatsoever.
To 30pmp ok using temp on maintainance jobs while your new bag of resin arrives, but eventualy you will get spotting
So it's fine as in you don't get any spotting on temp maintenance jobs till your new bag arrives, but magically, eventually you will get spotting. That did make me chuckle.
My internal O rings were worn on my 4040 and could not get the right spares anywhere, had to wait 2 weeks for the correct ones to arrive. At that point I went through my resin pretty quickly. With resin running out my output TDS went over 30ppm, but yet, the windows were not just "all right", but completely spot free.
ps. I'm not recommending everyone going out with high TDS, because there is a limit to it, but my HF-5 RO water is just fine.