SDXL LoRAs get the best effect when running on the models which they are trained.
This adapter LoRA let you run PonyV6 based LoRAs on Js2rpony with acceptable effect.
I use https://civitai.com/models/271989/muk-monsieur-style-for-pony-xl as an example:
PonyV6 VS Js2prony without using adapter.
Js2prony: using adapter VS not using