Book 5 High Guard does state:
That being said, I've hardly ever seen a 2 ton stateroom in any deckplan. Almost all are 3 tons.
Try doing the Type S in 3-D - they're two Tons, despite the number of square meters of floor.
The Type R is less than full height, as well - look at the the illos in CT:TTA 131 the center are 4 squares, but the edge (which are not full height) are (Starboard) 4.5 or 5 (port) squares...
The Xboat Tender has a bunch of 4 square (2 Td) cabins for its staterooms.
The Type S is 2m decks as drawn - except possibly in the engineering space. Whole threads about it. Given 2m decks, those are 2Td rooms despite 6 squaares.
The Type R in S7 has curved tops but is about 2.5m ceilings. So, yeah, oversized for the center ones. The outer ones, however, are under 2.5Td of cabin.
The Type A2 has an issue - it was drawn (apparently) with 1m grids, rather than 1.5, and then redrafted.
The Seeker, due to the same hull shape issue, has about 1.66 Td cabins of 4 squares.
The Gazelle has sloped sides; some of the affected rooms are 4 squares, and some 6 squares. None is more than 2.5Td in room.
The SDB has 6 squares, presumably 3 Td - but the commons are small.
That covers Supp 7.
The AHL has 6 square, 3Td cabins - but those are double occupancy.
The Leaping Snowcat (Adv 10) has about 2.5 to 2.75 Td due to the arched hull.
The Leviathan has few single-man rooms; most are double, and some are up to 4 man... and are 2 or 3 squares per man, as a rule, with 6 squares for officers.
The Kinunir has everything from open bays to suites...