with what that thing is i’d bet it’d have to be around 6.3 - 7.0 if added, especially when considering size, Low T/W, even if the engines are relatively strong for that BR, the top speed is very mediocre
and it’d probably handle like it looks - as a whale
now we can expect all planned ship and cruiser after 1941 got their hydroplane changed from KOR-1 to KOR-2 as it should. KOR-1, which even soviet navy decide not to be ship-borne and use as temporary till KOR-2 in service, took so many place in war thunder naval for years.
Depending on their implementation I would say 3 potentially great SPAA (SLM, Spyder and CS/S05), 1 meh SPAA (new ARH Type 81) and one straight up troll new SPAA (EldE 98).