This is a tool that I quick&dirty wrote, initially intended for non-English users, but it has some English compatible features as well.
https://ecarlo.nl/tse/ToolsAndExtensions.html#FindAlso
Requires GUI TSE with font Courier New or Linux TSE.
The FindAlso tool lets us use simple letters when searching for accented letters and special characters.
When you use this tool to search for a string containing ordinary letters and characters, the tool also finds:
The accented variants of the letters.
Ligatures (single characters that are combinations of letters).
Symbols described by a commonly used alternative of ordinary letters.
Some other non-ASCII characters.
The tool also always uses search options "ix" in addition to the options that you provide.
All TSE's search options are allowed and supported.
Examples:
"1/4" also finds "¼".
"(c)" also finds "©".
"oe" also finds "œ".
"tm" also finds "™".
"ue" also finds "ü" (a German custom).
"2" also finds "²".
"a" case-insensitively also finds the letters in "àáâãäåª".
"Espanol" also finds "Español".
"Francais" also finds "Français".
"Portugues" also finds "Português".
Carlo