PWA Extension Development setup recommendations

[lilbumblebear]

Getting started on developing some extensions for PWA! I have tried to read a lot of the documentation but I am still having trouble getting a good setup working.

If I want to develop several extensions, and test them on different storefronts, this is what I have done so far:

pwa/ 
   extensions
      extension1
          package.json
          intercept.js
          ...other files...
      extension2
   storefronts
      store1
          package.json
          node_modules
          ...other files...
      store2

If I include the extension in store1's package json using "extension1": "file:../../extensions/extension1" and run yarn install or yarn upgrade extension1 (when code changes) things work ok. However I have to yarn upgrade extension1 every time the code changes to see it in the store I am watching.

I tried using the yarn link proposed solution here, but when I run yarn watch I now have an error:

Error: Cannot find module '@magento/pwa-buildpack'
Require stack:
- pwa/extensions/productPageCheckout/intercept.js
- pwa/storefronts/store1/node_modules/@magento/pwa-buildpack/lib/BuildBus/BuildBus.js
- pwa/storefronts/store1/node_modules/@magento/pwa-buildpack/lib/BuildBus/index.js
- pwa/storefronts/store1/node_modules/@magento/pwa-buildpack/lib/WebpackTools/configureWebpack/configureWebpack.js
- pwa/storefronts/store1/node_modules/@magento/pwa-buildpack/lib/WebpackTools/configureWebpack/index.js
- pwa/storefronts/store1/node_modules/@magento/pwa-buildpack/lib/WebpackTools/index.js
- pwa/storefronts/store1/node_modules/@magento/pwa-buildpack/lib/index.js
- pwa/storefronts/store1/webpack.config.js
- pwa/storefronts/store1/node_modules/webpack-cli/bin/convert-argv.js
- pwa/storefronts/store1/node_modules/webpack-dev-server/bin/webpack-dev-server.js
    at Function.Module._resolveFilename (internal/modules/cjs/loader.js:902:15)
    at Function.Module._load (internal/modules/cjs/loader.js:747:27)
    at Module.require (internal/modules/cjs/loader.js:974:19)
    at require (internal/modules/cjs/helpers.js:88:18)
    at Object.module.exports [as intercept] (pwa/extensions/productPageCheckout/intercept.js:2:29)
    at pwa/storefronts/store1/node_modules/@magento/pwa-buildpack/lib/BuildBus/BuildBus.js:198:23
    at Array.forEach (<anonymous>)
    at BuildBus.runPhase (pwa/storefronts/store1/node_modules/@magento/pwa-buildpack/lib/BuildBus/BuildBus.js:186:20)
    at BuildBus.init (pwa/storefronts/store1/node_modules/@magento/pwa-buildpack/lib/BuildBus/BuildBus.js:167:14)
    at configureWebpack (pwa/storefronts/store1/node_modules/@magento/pwa-buildpack/lib/WebpackTools/configureWebpack/configureWebpack.js:130:9)
    at async module.exports (pwa/storefronts/store1/webpack.config.js:23:20)

I would like to be able to see extension changes immediately using hot reloading, without having to yarn upgrade each time the code changes. Does anyone else have this type of setup? How do you have things setup and working well?