Optimize js files sent

[PlopTheReal]

Describe the problem

My goal is to optimize the payloads and reduce the number of requests in a prod build.
Here are the requests on a page load from the route routes/[...catchall]:

My rollupOptions that reduces the number of chunks are the following:

rollupOptions: {
	output:{
	 manualChunks: (id)=> {
	    const chunks = [
		  'routes/+layout.svelte',
		  'routes/+error.svelte',
		  '...catchall]/+page.svelte',
		  '/components/critical/']
	       for (const chunkName of chunks) {
		   if (id.includes(chunkName)) {
			 return "m"
		}
	}
},

In the previous capture m.xxx.js are the merged chunks.

We can see those extra js files:
start.xxx.js
app.xxx.js
_layout.svelte.xxx.js
_...catchall_-page.svelte.xxx.js
0.xxx.js
1.xxx.js
2.xxx.js

Also some of them are nearly empty and probably don't require an extra request.

// _layout.svelte.xxx.js
import{O as f}from"../chunks/m.d03737c2.js";export{f as default};

// _...catchall_-page.svelte.xxx.js
import{R as f}from"../chunks/m.d03737c2.js";export{f as default};

// 0.xxx.js
import{O as m}from"./m.d03737c2.js";export{m as component};

// 1.xxx.js
import{Q as m}from"./m.d03737c2.js";export{m as component};

// 2.xxx.js
import{R as m}from"./m.d03737c2.js";export{m as component};

The page loaded is from [...catchall] route:

Describe the proposed solution

Remove / merge as much js files as possible.

Alternatives considered

No response

Importance

would make my life easier

Additional Information

No response

[PlopTheReal]

I've just spotted that this one is related to ##9520 and ##3882

[dummdidumm]

Closing in favor of those referenced issues

[PlopTheReal]

feels sad, looks I've provided a bit more 'up to date' details / insights in this one.

[dummdidumm]

No worries, it's not for nothing! The referenced issues do link back to this one so we will not lose sight of the details in here.