The dragon stone (ohko) is not incompatible with shrimp. To test stone compatibility with shrimp: make sure it does not fizz when you put a strong acid on it. Then let it soak in pure RO water for a day and check if the TDS rises. IF it does, then your stone is leeching something, and you need to take it out.
If you use SS GH/KH and remineralize to GH 7 or 8, the TDS should be around 160 or so.
In your case, you can buy SS GH only and use that to make your water. For now, you can also mix in some of the GH/KH so the change is not sudden. Eventually, you will have a pH of mid 6's. Maybe mix in a small amount of the GH/KH so you have kH near 1 and pH upper 6's. Cherry and neo shrimp can live in these conditions, but might need some specific food supplementation. I had neos living in these conditions for several months, (over) feeding with a variety of foods, but when I reduced feeding to have them live off the tank biofilm, they died in a few weeks.
A big KH change is tough on neos, so even a slow acclimation might not be slow enough.
You can also swap out your substrate. There are other brown, round pellet type substrates that are a hard-fired clay which you can't crush with your hands, and they won't change the water parameters either.