Hi Codee,
Yes, Tim's method is straight forward and will certainly work well.
You can also run UPDATE statements if you're comfortable. Make a backup and proceed with caution.
For example, these two statements would update the uploads table filePath and urlPath fields (finds and replaces ending .jpg with .webp):
UPDATE cmsb_uploads
SET filePath = REPLACE(filePath, '.jpg', '.webp')
WHERE filePath LIKE ('%.jpg');
UPDATE cmsb_uploads
SET urlPath = REPLACE(urlPath, '.jpg', '.webp')
WHERE urlPath LIKE ('%.jpg');
If your site uses thumbnails then you'd need to do the same process for each thumbFilePath and thumbUrlPath (thumbFilePath2 and thumbUrlPath2; etc up to 4).
To note, if all of your images were converted .jpg to .webp using the plugin this will work.
However, if you have "Use WebP" active in general settings, any new uploads appear to have the previous file type appended to the filename (ex. "myimage.jpg" would become "myimage-jpg.webp", which would require modifying the update statement replace '.webp' portion with '-jpg.webp').
Make a backup, and backup the backup :) Good luck!
Best,
Steve
P.S. I'd already started drafting this and didn't see your post update until complete :) Glad you got everything working again! I'll leave this up here in case it's useful in the future.