Well, the idea of "short vowels" is not really relevant in Bosnian. Bosnian Perso-Arabic wrote every single vowel, just like Kurdish, short or long, stressed or unstressed, etc. It is a true alphabet.
So some random examples from Wikipedia:
پرەما - prema (prhma or prema) - the unattached h is used to mean "e" otherwise it would look like this پرهما (literally prhma this time)
سوەتا - sveta (svhta or sveta)
دۉستۉيانستوۆ - dostojanvstvu (dwstwjanstvw or dostojanstvu), definitely not dstjanstv as Arabic would do.
Since Bosnian Arebica used consonant diacritics (s/š, c/č) , it is a 1:1 with Bosnian Cyrillic. There's a letter for every vowel and lj and nj are their own letters (not L+J, but љ or ڵ). There is no use for Arabic vowel diacritics مَمِمُمّمْ to indicate short vowels, gemination and such.
In that sense, the only different between Cyrillic and Bosnian Perso-Arabic is that the latter is right to left and the cursive-like rules for joining letters. There would be no difference when typing on a computer keyboard because the joining is automatic.
Bosnian and Belorussian are two different systems.
I don't know much about Belorussian Kitabs, but from what I've seen on the Internet (some low-resolution images), it seems that they use vowel diacritics, which means that it is closer to Arabic in dealing with short vowels. Having that said, it doesn't mean that they're not written or that they're necessarily optional. It just means that they're smaller. So think of "re" being represented as rᵉ or mi written as mⁱ or ko as kᵒ.
So this is three ways of writing bolo:
All three can claim to be 1:1 of bolo and true alphabets. The first is just b-o-l-o, the second has letters joining, the third has joining letters but uses: ُ
which are the same symbol, except one is much smaller, is aligned much higher and does not connect. Removing these diacritics, however, would make reading into a guessing/memory game and would make the alphabet no longer a true alphabet. The size or alignment of some of the vowels does not change the classification of an alphabet. Writing like this: "WᵉLCᵒMᵉ Tᵒ THᵉ JᵘNGLᵉ" doesn't change anything, but this "WLCM T TH JNGL" certainly does.
So in short, Bosnian does بولو while Belorussian does بُلُ.