https://en.wiktionary.org/wiki/fore
https://en.wiktionary.org/wiki/four
The IPA suggests that pronunciations of the two words are identical both with and without the merger, but I'm no specialist.
In accents with the merger, "four," "for," and "fore" are all always homophones.
In accents without the merger, "four" and "for" are never homophones.
And in some subset of these non-merged accents, "fore" may be pronounced identically to "four" (as listed in the IPA guide in your first link). In another subset, it may be pronounced identically to "for" (as implied by the "Homophones" section in that same link).
It is extremely hard for me to even _imagine_ this, as apparently my native accents both contain this merger. This is a rare experience for me, but a previous occurrence was discussing the rhotic-R phenomenon.
> Accents that have resisted the merger include most Scottish, Caribbean, and older Southern American accents as well as some African American, modern Southern American, Indian, Irish, and older Maine accents.
If my understanding is correct, in some accents that don't pronounce their "R"s at the end of words, the vowel shape changes slightly while pronouncing "four," but "fore" is pronounced with a simple vowel.
[1] https://en.wikipedia.org/wiki/English-language_vowel_changes...