It’s not quite resolved.
For others who find this support request, the plugin had a bug introduced in version 2.0.12. This bug caused the plugin to fill up the database. The database in my particular site went from approx 200MB to over 50GB in the course of 24 hours, growing at about 1GB per 30 to 40 minutes. The bug is said to have been fixed in version 2.0.13. The BSF support team suggested I upgrade the plugin to version 2.0.14, which was already in use within my site.
The solution I came to was to delete the excess data. BSF were unable to advise me whether doing so would affect Spectra blocks in posts and thus affect the content of posts that contained Spectra blocks. I still have had no reply on this.
If your database is overflowing because of the fixed (?) bug in Spectra you can use the following SQL query in PhpMyAdmin to delete those superfluous rows of data (there should be backticks around wp_options, option_name and wp_collect_spectra_blocks_count_batch_%).
DELETE FROM
wp_optionsWHERE
option_nameLIKE ('wp_collect_spectra_blocks_count_batch_%');
0. Take a backup of your database first, if you can do.
1. Open the affected database in PhpMyAdmin
2. Go to the SQL tab in PhpMyAdmin
3. Place the SQL query into the form and change wp_options to the name of your wp_options table.
Good Luck!