For the record, I can see that Chrome DevTools attempt to restore breakpoints, but their DOM breakpoints UI seems quite buggy (after a reload, the DOM breakpoints get duplicated in the Sources panel) so I'm not sure we should use this as reference.
Bug 1790057 Comment 3 Edit History
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For the record, I can see that Chrome DevTools attempt to restore breakpoints, but their DOM breakpoints UI seems quite buggy (after a reload, the DOM breakpoints get duplicated in the Sources panel) so I'm not sure we should use this as reference. Edit: And they restore by xpath apparently, so the element on which the DOM breakpoints are re-added after reload might have nothing to do with the existing one. And they don't only restore on reload, they seem to keep track of DOM Breakpoints per URL. So if you go to mozilla.org, set a DOM breakpoint, go to wikipedia.org and go back to mozilla.org, the DOM breakpoint will be restored (again by xpath, so not necessarily on the element where it was "initially" added)