☒ , you can probably mitigate this from a visual perspective by removing the "fade" class

<div class="modal fade" data-controller="modal">

to 

<div class="modal" data-controller="modal">

That's strange, I removed the fade class, and while it did remove some of the animation functionality, it did properly display the persisted form while submitting and getting a server response.

gitpod looks interesting. My main concern when working with a remote dev environment is the ability to use the native tools on my computer. I really dislike the browser based editors like you would find with Cloud9.

Absolutely. For a more detailed look into optimistic locking, there is a recent episode on the topic. https://www.driftingruby.com/episodes/optimistic-locking

This answer on StackOverflow may shed some light. https://stackoverflow.com/a/59907030