I expected some special syntax like post:id!community@domain

Or ap_id?post/15@xn--e1aghfa.xn--e1aqbccjfc.xn--p1acf

Here ap_id is the name of part of URI, which maps to
https://lemmy.ml/post/ap_id
and performs all the magic, which lemmyverse.link does

Or https://lemmy.ml/post/49064481?15@xn--e1aghfa.xn--e1aqbccjfc.xn--p1acf
if developers will integrate it into lemmy itself

?=post/15@xn--e1aghfa.xn--e1aqbccjfc.xn--p1acf - any ap_id

?[!community@xn--e1aghfa.xn--e1aqbccjfc.xn--p1acf](/c/community@xn--e1aghfa.xn--e1aqbccjfc.xn--p1acf) - any community
?usernick@xn--e1aghfa.xn--e1aqbccjfc.xn--p1acf - any user
but the last two options are not necessary