In M-Team, HD-Torrents, CHDBits, OurBits and HDCMCT there is your torrent but only on Bluray 4K (60 GB):
https://i.loli.net/2018/04/29/5ae4d8e016143.jpg
to find IMAX torrents just write "IMAX" in the search bar on your trackers
In many chinese trackers there are several IMAX Blurays like these ones (and more):
https://i.imgur.com/5aWt9Ju.png
https://tpimg.ccache.org/images/2018...703ae76157.jpg
https://s1.gztown.net/2018/04/21/IMA...f1edb03172.png
https://tpimg.ccache.org/images/2018...cbbe96e79a.jpg
https://tpimg.ccache.org/images/2018...45deb5ba4b.jpg
Also PrivateHD has some ones