- When using a custom cacheHandler locally or self hosted, each ISR enabled paths will trigger cacheHandler.set(key, data, ctx), with the key being the path of the route (ie /fr-fr). This allows to manually manage cache creation and invalidation.
- When using a custom cacheHandler on Vercel, the ISR cache seems managed by Vercel and completely bypassed from the cacheHandler. The problem is that Calling revalidateTag will not trigger Vercel ISR cache invalidation when cacheHandler is enabled.

Is there any way to revalidate Vercel Data Cache from a custom handler? Can a custom cache handler be used on Vercel?