here is a simple patch to make isearch highlights non-sticky at both ends (i.e. no front and rear advance on overlays), thereby making them more intuitive and less bothersome for further editing. Currently, every isearch overlay, including lazy highlights, inherits isearch highlight color when you type characters at front and rear positions. By applying this patch, users will no longer get that color stickiness when editing around isearch highlights, which makes them more 'self-contained'.

(This is the first time I am submitting a patch to this community - apologies in advance if I am not following the conventions in some way.)