its a good plan for sure, wait a bit then complete it out
in my opinion don't use bottle bac. that's not because I think your system would be harmed/long track record of not killing people's tanks here/but because it takes bravery to step outside the control boundaries of bottle bac sellers who've trained us merely glancing at a reef tank requires 3 bottles to 'stay alive'
what you're planning is an algae risk, not a crash risk and I know you're already planning for the uglies
hey that's a perfect reef though, why jack with it???

it is very nice. however you guided that through the uglies will be just fine on the new rocks too. in my opinion more jobs done without bottle bac puts the power and control of cycling in the hands of reefers and not sellers.
in our tank transfer thread which is sixty pages of mixed tank transfer jobs the #1 thing that was a crash risk was the upwelling of waste up under rocks and in the sandbed. that looks clean and managed above, but creating clouds in the tank of detritus waste formerly held in place was the real risk and you've already got past that step so there's no reason to think removal section #2 will matter via clouding. at day 20 I would trust it and I'd really like to link your thread to that one since you're doing a non bottle bac job, one that is a calculated wait/deposit time only.
very new wave stuff to not be dosing bottle bac right and left. and if you already have, I forgive you he he