I'd def recommend the revised version of HDG, it's a lot better edited and has some additional stuff =)
(The final two chapters of the Elvira arc should be out within a month or two, fingers crossed!)
Other than Courtship, Abscission, and Divaricated, which Celeste already mentioned (and are very very very very very good), consider (in no particular order):
Petals and Vines by my gf Evening, which is a delightful cute romcom
Bureaucratophilia by Dame Harmony, a blisteringly hot examination of just how bureaucracykink is hot in the first place
Dandelion Fluff, Real Affini by Angelmoon, in which the terran cosmic navy's cutest girlfailures hatch a plan to 'save' themselves from domestication
Sick Day by squircularlogic, where an affini gets the human fake-sick so that she understands just how much she needs her affini's care
Florets of a Feather by @hdgprom , where a human gets domesticated and her new pinnate slash sister is a cute cat xeno!
Wax and Vines by @ufo-wanderingsun , which I finished a few days ago and can't stop thinking about. I wrote about it a bit more here
Wellness Check and @darkfalli's other works are also classics!
Accident on Aisle Six by @foxgirlmindcrank , if you like abdl you owe it to yourself to read this (and the sequel!)
Little By Little by @immaterial-vivi , which is also abdl and very cute and hot!
There's lots more I could recommend but I don't wanna just list the entire tag on AO3 at you so I'll end with the suggestion of my own Sweet Like Cocoa, a very noncon cgl regression story that I'm very fond of ksjdfhgdfgkdfjs