Most dictionaries indicate that “boor” is pronounced with a long a. As I said, Boer has several variants listed.
The Mexican sauce is pronounced mo-lay.
Something close:
Zombie
Zombie
Zombie
Zombie
All four words are spelt the same and have the same meaning …
ETA: They’re all pronounced the same too …
In what dialect? Around here, “zombie” and “zombie” are pronounced completely differently (though they are both pronounced the same as “zombie”).
Assuming you meant “o” and not “a”, this in no way contradicts Ludovic’s claim that the pronunciation varies by dialect. Indeed, your assertion that only “most” dictionaries give this pronunciation implies that at least some do not, so obviously the other pronunciation(s) are common enough to have attracted the attention of lexicographers. I can personally attest to having often heard “boor” pronounced with the same vowel as “bore”.
I agree and I don’t think it’s subject to my NY ear. In many Southern accents they call the thing you write with what we call something you’d stick yourself with and spell p-i-n, a pin. And the majority in many such states don’t vote for the Dimocrats (not intended as an insult, just how it’s pronounced). 
In at least some Southern accents though the thing you’d stick yourself with I agree is more like a pee-in. Maybe in some sorta Southern places you write with a pin and stick yourself with a pin, and thus pen and pin are heterographs. Nut in the Old South in general I’d say not.
TIL from a zombie that the rest of the Anglophone world pronounces gnu with a silent G (except England where some seemingly consciously pronounce a hard G because of a comic song - imagine if the English all said keniggits as the default because of Holy Grail.)
Maybe it’s because the word comes from here, but I’ve always pronounced it with a hard G.
I assume the “long a” was a misprint for “long o.” But the vowel of ‘boor’ (rhymes with ‘lure’) is not what was called ‘long o’ when I went to school, IIRC. I think that sound was called ‘long u.’ ‘Long o’ was the vowel in ‘boat’ or ‘bore.’
I’m curious whether there’s any debate about the constraint ‘must work as a standalone word’. It seems key, otherwise loads of different characters have the same pronunciation, right? This is generally even more true in Korean with no morphological tonality, somewhat offset by ending vowel sounds and more variation in starting consonants and vowels aside from tone, eg. the characters above are se, seok, seo, ssi, seo and shi respectively in Korean. But there are for example 37 characters in the ‘okpyeon’ (a Korean Chinese character dictionary) app on my phone which are shi (시 in hangul). There are 7 standalone words (including two prefixes) shi (시) in an abridged dictionary:
市 (시) city
時 (시) time
詩 (시) poetry
시 (indigenous) a musical note
시 (indigenous) an exclamation like ‘damn!’
시- (indigenous) prefix, vivid, like a color
시-( 媤) prefix, pertaining to a woman’s in-laws
Going to just the next hangul-alphabetic entry in a Korean dictionary there are at least 9 two syllable words which are spelled 시가 in hangul, shi-ga, though only 6 are common enough to show up in abridged dictionaries:
市街 city street
市價 market price
始價 opening price (say of a stock)
時價 current price
時價 Chinese homophone for previous, length of note or rest in musical notation
媤家 one’s husband’s family
詩家 (less common word for) poet
詩歌 poems and songs or just poetry
시가 the English word ‘cigar’
Looking extensively, armed with a big dictionary, I’m sure someone could come up with phoneme combinations with more examples, of Korean heterographs in the sense of having different underlying Chinese characters (or Sino-Korean v indigenous/foreign loan), though in theory if two words in Korean are pronounced the same way they must be spelled the same way in hangul (with relatively few real world exceptions).