[democrite]

Thinking of search and replace in general, or other forms of automation, a greater thinking of how such might be done may lead to revisiting any aspect of how they are done now. Maybe some external file as you suggest, maybe instead labeled groups of saved searches (e.g. for me many replacements or use of TagMechanic differ by publisher), or something else.

For me, I tend to always try to think of what is easiest to create, maintain, and whatever takes the least amount of mouse clicks or keystrokes, e.g. like being able to go to css definition from cursor position, refactoring/removing some tag, attribute, class, etc. from cursor position also would be easiest. Though I understand such features compared to other IDEs or editors come from commercial or larger projects with a larger team, perhaps difficult for Sigil itself.