First of all, Chem Geek, absolutely no offense taken... I didn't write the article, I just thought it was worth reading (especially for newbies to TDS).
regarding adding chlorine to bromine: I thought we ( waterbear & chemgeek & I) discussed this as a bad idea in another thread lol

I dump the tub water about every three or four months, although timing can be quite important in winter... no one wants to do the empty-refill maintance in a blizzard.
I do use quite a bit of chemicals for start-up ( not just throwing some pucks in). I also have two chemicals for cleaning the filters which I do every month.
not to mention " tub clean" a very acidic chemical that you run through prior to draining.. ( eat your skin off! & so stinky too)

My primary hot tub, although outdoors, is essentially an almost "closed system". The cover is always on, unless we are in it... ( steam doesn't even escape it in the coldest days of winter). It is a completely independant system & this may make it "behave" differently than waterbear's tub which is part of his pool system.

I don't "shock" my tub per say ( except for start-up), but I do bring the levels up quickly ( & probably in-fact shocking it); We often throw some "bromoblast" in the tub as we get into it. We actually prefer to keep our tub at 10+ppm; this really helps my DH with some troubling skin conditions that he used to take medication for, prior to getting the Tub.
( and if you have any pus sores, the high bromine seems to draw out the infection & help the healing process as it dries out the sore & seems to close it up too.... Also cures diaper rash! lol... & strips my hair of colour beautifully.. )

As I said before I prefer the tub at a TDS of 800- 1000 ppm.I would be happy to just partially drain & refill, just to keep the TDS at that level.- I don't like the feel of high TDS water ( or low TDS water for that matter...lol). But I worry about the safety issues of residual bacteria living in the "pass-through" area of the motor/heater... ( I have a large amount of piping there... it may be like a tankless water heater, but it is several feet of piping)

( why is it difficult to believe that when there is tons of crap in your tub, or high TDS, that your sanitizer might get 'busy" with all that & that it won't be as effective? is it not plausibile?)

( also note that if you add fragrance for every tub-ride, you'll hit the high TDS mark very fast as well. & I suspect that the fragrance binding/bonding materials interfer somewhat with the sanitizers, although I have no proof of that. lol)

So maybe it isn't "important" if you are draining every three months... but for those people who don't; TDS monitoring is a good reminder of when to drain.