Pretty easy to add amendments once you get the hang of it.
This man speaks the truth.
Since my dry amendments are light (not hot, won't burn, etc.) I can actually top dress every 1-2 weeks and the only negative side of that is potential diminishing returns.
I prefer to apply dry amendments with light NPK ratios every 1-2 weeks as opposed to high NPK ratios once a month. Less chance for burn, and this ensures your plants (soil, more specifically) will always have everything it needs.
I use a 5-5-5 mix, plus Neem Meal (6-1-2) for veg, then I use a 3-8-4 mix with Karanja Meal (zero NPK, but same benefits as Neem) for my top dress in flower.
The whole point would be to have a water only mix so when I recycle my soil after each harvest I can add some dry amendments to tweak it so it’s exactly what I would need.
Look into No-till. You'll have to account for soil compaction, but no-till will always provide better results than ROLS because you aren't destroying the web of microbes that developed over time.
Picture microbes as a town. When you dump the pots, the microbes have to start all over again and "rebuild" their town essentially.
If you run no-till, that town not only doesn't get destroyed but will grow into a full blown metropolis.
Just cut the plant at the base of the stem come harvest, then pop a new clone/seedling in the pot immediately. If you don't plan on using the pot again immediately, that's fine too. Simply keep it watered/moist and top dressed so the microbes can survive and keep doing their thing.
No need to dump and mix, unless that's what you'd like to do. You can just as easily plant a new clone/seedling in the pot and simply top dress with the amendments you were going to mix back into the soil.