Hello,
There’s version 4 of the Sparky Framework that’s compatible with Joomla 4. So, after you upgrade your site to Joomla 4, the frontend of your site could be broken, but then from backend you install Sparky Framework 4. All the settings will be kept (unless you are using too old template).
We will start releasing template updates for Joomla 4 and all templates will be updated. If you are using a template, you better wait. If you are using the framework only, you can upgrade yourself.
Thanks,
Milos