I’ve got a custom block and have used it extensively. Is it possible to now change the name of this custom block snippet and blueprint - without loosing all the content already in the block?
I’m nervous to try it in case I loose all the content have to re-enter it. I suppose I could do a find/replace in the Content files, but that seems a bit of a faff?
If you rename the files belonging to this custom block, then yes, you will have to replace the block name in your content files, either through find and replace or programmatically.
If you just want a different label to appear in the Panel, change the block name in the block yaml instead.