Updating frustration

While performing markup updates to page content I am experiencing non-responsive pages. I finally receive a http 429 error when trying to save: 429 Too Many Requests. This means I am being rate-limited on the server side which is incredibly frustrating,
The workaround I discovered appears to be editing the markdown outside of Squarespace and uploading (I use MacDown on MacOS). All pictures should be uploaded too so there are no broken links.
Squarespace were not much help, stating they don’t offer assistance for ‘custom code’.

Go figure.