Sadly the 3D release of Avengers Endgame did not come with any opened up IMAX scenes so I have used the Russian Open Matte stream, that has more image on the top and bottom compared to the 2160p WEB-DL, as the main source of this release.
One definate advantage this Open Matte version has over the other Marvel IMAX releases based off the 3D blu-rays is that it does not have the left sidebar changing width from shot to shot.
2160p WEB-DL 1:
Regraded 1:

2160p WEB-DL 2:

Regraded 2:

2160p WEB-DL 3:

Regraded 3:

2160p WEB-DL 4:

Regraded 4:

2160p WEB-DL 5:

Regraded 5:

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : [email protected]
Format settings, CABAC : Yes
Format settings, RefFrames : 4 frames
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 3 h 1 min
Bit rate mode : Variable
Bit rate : 2 598 kb/s
Maximum bit rate : 10 000 kb/s
Width : 1 920 pixels
Height : 1 080 pixels
Audio
ID : 2
Format : AAC
Format/Info : Advanced Audio Codec
Format profile : LC
Codec ID : 40
Duration : 3 h 1 min
Bit rate mode : Variable
Bit rate : 447 kb/s
Maximum bit rate : 526 kb/s
Channel(s) : 2 channels
Channel(s)_Original : 6 channels
Channel positions : Front: L C R, Side: L R, LFE
Sampling rate : 48.0 kHz
Frame rate : 46.875 FPS (1024 SPF)
Compression mode : Lossy
Stream size : 582 MiB (15%)
Title : avengersendgame.aac