Honestly yeah I've never read a read where they portrayed it accurately them merging sounds pretty realistic on my end though considering there was only a barrier because of his belief that he wasn't good enough when he wasn't performing along with his hatred towards himself often believing his love was dangerous you can see as the story progresses hes able to heal from those chains and eventually merge into well this
Although often times there isn't a one size fits all cure for DID and its moreso something we've grown to live with, you can tell in his case he needed to merge in order to survive in other words he was finally able to reveal himself
It's quite the ride but I really like it. There's never amazingly accurate depictions of dissociative identity disorder in yaoi but of the ones I've seen this is definitely the best funnily enough. Unlike 'Absolutely Ruined Love', the personalities merge at the end which is more accurate to real life DID recovery. They are just separate parts of one whole.
As for the other BL I previously mentioned the personalities never merge and the ML just never technically recovers from DID.
Definitely not for everyone but I was a fan ( ꈍᴗꈍ)