Can't pass unstable flags to tasks

[lishaduck]

I'm trying to write tests using Vitest for @lishaduck/effect-platform-deno. I use deno task to run the invocations, but I can't pass unstable flags. I know I could use deno test, but I want to eventually upstream it into Effect, which uses Vitest.
I've tried deno --unstable-kv task test, which failed with "unknown option" and deno task --unstable-kv test, which worked, but didn't pass the flag on.
deno --unstable-kv ./node_modules/.bin/vitest run worked, but I feel that there's probably a better way to do it I'm just missing (If not, consider this a feature request).