OK, so rather than have one “Accordion” block, I just added a bunch of core Details blocks instead which worked for our requirements.
The only custom thing we had to do was to add some JavaScript to automatically close the other Details blocks when one was opened.
We actually added this as an option to the Details block in a plugin that we develop to make it easier for us to repeat in the future. If you’re interested I’m sure you can find the plugin on my www.ads-software.com bio but there may be other plugins out there that already do the same so don’t want to name drop ours.
We tried to get this option added to the core block over a year ago but the proposal was not deemed suitable which is why we’ve done it ourselves. As I’ve mentioned before, there will eventually be a core Accordion block I’m sure but for now this works for us.