I didn't find it triggering, and I kind of liked it. I've always had a vision of how to portray DID on film and this is not far off. My own involves animation over live action rather than straight live action. I have to say, I did not like that he is shown first in a padded room in a hospital, that is very inaccurate and stigmatizing. As someone in the comments noted, the great majority of us are not institutionalized.
It's really too bad that the sensationalized treatments have proliferated because a genuine and respectful portrayal of DID on film could go very far in raising awareness and sensitivity. There are some beautiful moments that could be captured. Sometimes I wish I could type fast enough to make transcripts of internal exchanges, there can be complex relationships between parts. I try to show this in my artwork.
I did like the film, did I say that?