Describe the solution

I have a SvelteKit based framework Worker. This is using the @sveltejs/adapter-cloudflare adapter which uses Wrangler's getPlatformProxy API under the hood to provide a great DX with vite dev for local development. I'm able to use bindings to D1, KV, etc. and have hot module reloading from Vite.

When I tried to add a Durable Object binding, which I was running in a separate wrangler dev, I ran into the error:

Error: Cannot access `MyDurableObject#sayHello` as Durable Object RPC is not yet supported between multiple `wrangler dev` sessions.

Reading in the Docs, I can only do Durable Objects RPC when a single wrangler dev uses multiple configurations:
https://developers.cloudflare.com/workers/wrangler/api/#supported-bindings (related to #5918)

This would require me to build both the SvekteKit and DO workers before spinning them up in a single wrangler dev session. Therefore I would miss out on hot module reloading with Vite, significantly slowing down the DX.

Feature Request

I would like to request adding support for multiple configuration files to the getPlatformProxy API, to provide a similar solution as the multiple config files with wrangler dev.

In the svelte.config.js file, I would be able to conditionally pass in multiple config files depending on environment (local development vs production), since the SvelteKit adapter accepts a platformProxy prop on the options, which is passed to getPlatformProxy.

Currently, the getPlatformProxy options allows to specify a single config file with configPath already. Maybe this could accept an array of strings as well?

If that allows the framework worker and DO worker to communicate via RPC, then I can keep having the nice hot module reload DX with Vite, whilst depending on a Durable Object for persisted storage during development.