But there's no feature that points to Sirius.
There are other temples with similar alignments, but if you look at them, you will find that there's no doorway or street that points in the direction of the spot where Sirius is to rise. There's walls in the way. There is no way of observing the event from within the temple grounds.
When they align the temples with other objects in the sky, there's always a clear line of sight to that object and there are processional causeways leading to the temple that match the alignment. Karnak is a fine example of this.
In order to prove a Sirius connection, you have to show that they kept this standard; aligned the temple so that the heliacal rising of Sirius could be seen from the naos in the main part of the temple itself. The naos is the inner sanctuary of the temple, where the ... hmm... "living statues" of the deity being honored would stay. This is usually the room farthest from the main gate. At Karnak, you can see that the sunrise can clearly be seen along the great avenues and in the temples at the solstice.
The temples you identify as having a "Sirius" alignment have their main doors and causeways aligned with the circumpolar (the "Undying") stars.
See Shaltout, Mosalam, Juan Antonio Belmonte, and Magdi Fekri. "On the orientation of ancient Egyptian temples
3) Key points at lower Egypt and Siwa Oasis, Part II." Journal for the History of Astronomy 38.4 (2007): 413-442.
-- Byrd
Moderator, Hall of Ma'at