Just to make sure you saw it, this is what it says on the website I linked you to:
These theatres never really have ‘good’ legroom so with your height picking the extra legroom ones will probably have been the best bet if it’s a concern.
Legroom
Good in rows E to ZB, adequate in rows A to D, and outstanding in row R seats 2 to 15 and 33 to 46 which have aisles in front, as well as ZB which has extra distance between the seats and row in front.
Seats B11, 12, 36 and 37 also have nothing in front.
Seats A 17 and 30 have a metal pillar in front, meaning feet go either to the side (except when the stairs are in use) or under the orchestra rail in front slightly. Legroom in central A is adequate up to 5ft 9, around 2 inches less in the side blocks as they curve a little more.
These theatres never really have ‘good’ legroom so with your height picking the extra legroom ones will probably have been the best bet if it’s a concern.