I know Rob is a big time shrimp breeder and I'm a guy with a few shrimp tanks, so by all means weigh that in when I say that I don't agree with his advice here. I disagree mainly because I've done it out of laziness in my own cull tanks and it's not a good long-term plan in my experience. No doubt you can get by with top offs only for a long time with the minute amount of waste that is produced by a shrimp colony. Where I'm breaking from his line of thinking is that there's a lot more going on in a planted ecosystem than just the nitrogen cycle and bioload. Eventually I feel that's what has caught up to me when I've had big colonies in old tanks suffer water changes poorly. Whether using tap or remineralized RO water, that tank is getting a little further from the source water by the day. This is why I feel like 10% weekly is kind of a sweet spot. I get where Rob is coming from in terms of short term stability but you can only do top offs with no water changes for so long. At least with weekly small partial water changes, while the slight shifts in parameters will be frequent, you avoid ever having large ones that could potentially wipe out colonies.
But having said all of that there's no rhyme or reason to what does well in my own tanks or I'd have a system down. I have a 5.5 cull Neo tank currently that I do 50% on weekly-ish. It's doing great. My shrimp rack with fancy lines gets 10% weekly. 3 of those 4 are doing well. My planted 125s with fish and shrimp get water changes when they need it and I have time. Those are big tanks and I'm always shaking babies out of the Python. None of these approaches appears to demonstrably work better than the next and the shrimp colonies seem to take turns farming babies and then just holding steady. Except the OEBTs, which have never had a fry as far as I'm aware. Maybe it's something to do with the line? I know we got ours from different breeders. It's something I'd love to figure out.
Nothing good happens fast in an ecosystem.