plunking (note Deno.mainModule)

circ/a.tsx

@@ -0,0 +1,13 @@
+import { doSomething } from './b.tsx';
+
+export function doSomethingElse() {
+
+    if(Deno.env.get("a") && Deno.env.get("b")){return;}
+
+    Deno.env.set("a", "called");
+    console.log("a action");
+
+    doSomething();
+}
+
+import.meta.main

circ/b.tsx

@@ -0,0 +1,10 @@
+import { doSomethingElse } from './a.tsx';
+
+export function doSomething() {
+
+    console.log("b main?", Deno.mainModule);
+
+    Deno.env.set("b", "called");
+    console.log("b action");
+    doSomethingElse();
+}

circ/start.tsx

@@ -0,0 +1,3 @@
+import { doSomethingElse } from "./a.tsx";
+
+doSomethingElse();

lib/iso.tsx

@@ -2,15 +2,25 @@ import TWPreTail from "https://esm.sh/v115/@twind/preset-tailwind@1.1.4/es2022/p
 import TWPreAuto from "https://esm.sh/v115/@twind/preset-autoprefix@1.0.7/es2022/preset-autoprefix.mjs";
 import React from "react";
 
+import {INIT} from "../server.tsx";
+
+function wrapper()
+{
+    INIT();
+}
+
+wrapper();
+
 export const CSS = {
     presets: [TWPreTail(), TWPreAuto()],
     hash:false
 };
-
+/*
 if(!window.innerWidth)
 {
     import(import.meta.resolve("../../server.tsx")).then(()=>{console.log("...imported!");});
 }
+*/
 
 type MetasInputs = { [Property in MetaKeys]?: string };
 type MetasModeArgs = {concatListed?:boolean; dropUnlisted?:boolean};

server.tsx

@@ -10,6 +10,8 @@ import * as Iso from "@eno/iso";
 
 Deno.env.set("initialized", "true");
 
+export const INIT =()=> console.log("init!");
+
 /**
  * Setup a transpiler.
  * @param inDevMode When true, starts a file-watcher
@@ -282,6 +284,14 @@ Deno.args.forEach(arg=>
     }
 });
 
+let Booted = false;
+export function Boot(inApp:React.JSX.Element, inCSS?:object)
+{
+    if(Booted){return;}
+    Booted = true;
+
+}
+
 let DevMode = Flags.dev ? true : false;
 let hosted = import.meta.resolve("./");
 const Path = {