Thanks for your review!

The marker feature in this addon is auxiliary, and was originally conceived purely to highlight text temporarily until the first page reload. After adding the ability to save markers for permanent use, I came to the conclusion that it would take much longer to fully implement the feature than expected - I had ideas to split the extension popup into two sections (settings and markers), show a bubble with the number of markers on the page when they were found, fix the incorrect marker recovery with large selections, and so on.

All of this would undoubtedly take over the development blanket, so I've decided to leave the feature as it is for now - with awkward management through settings and a few bugs. But I'm glad to hear that you found it useful! Perhaps over time I'll revise the feature in favor of deeper integration into the addon.