my cyrillic is based on present-day russian... excact same spelling rules except they pronounce their soft C's, D's, S's, and Z's quite differently than the polish do. Also, they don't have RZ sound like Polish does. So their word for rzeka would be spelt река
, but pronounced like 'rika'. Also, no modern cyrillic alphabets use the Yus symbols any more, considering they no longer contain nasal sounds in their words. Since polish still does, we would have to bring them back from the dead. :D ... the use of ± and ę in cyrillic just doesn't look right.
and the hard signs at the end of words does look nice but it went out of use after 1917...
realistically, modern day Belarussian writing resembles almost exactly what polish would look like written in cyrillic, except for their letter 'ў'....
another thing is that Nikolay I's example is based on old russian cyrillic with the used of letters ць and дзь to resemble ć and dĽ - which is what Belarusian uses today, as what as Polish in latin... but ć is softened form of T, which dĽ is softened form of D... so using ть and дь is tecnically more accurate. Czech and slovak used the proper forms of these two in the forms of Ď and «.
Same reason why serbian/croatian use ć and ћ in cyrillic,,, their ћ is just like russian ть.
hence serbian браћa is just like russian братья (pronounced like bratja), and polish bracia.
i'm not good at explaning this stuff.. :P