Just in case people need a little guidance in how to get all three endings, I decided to make a brief walkthrough.
I'll be posting a new walkthrough once I finally get around to throwing Jing Yuan into the mix as well with the next update. As things will be getting a little more complex in part two. ;)

Light spoilers ahead ~

Most of the choices in the vn are just for roleplaying with some minor changes in dialogue. Then there are some 'physical affection' scenes during the romance routes, such as holding hands or the make out session. These are all entirely optional and do not effect which ending you'll get. I did it this way because I know people have different comfort levels when it comes to showing physical affection. So if you're uncomfortable with reading descriptions of Dan Heng and the Trailblazer making out with one another in public, you can skip that scene without fear of consequence.

When it comes to getting the ending you want, there's only two unique choices you need to focus on ...

Friends Forever Ending
When Dan Heng leaves the decision up to the Trailblazer about whether they're on a date or not, make sure you reply with:
"Let's just stay friends." This will automatically lock you into the friendship route. As Dan Heng just assumes the Trailblazer isn't interested in starting a relationship at this time. Note that in the future there will be an opportunity for Dan Heng to confess his feelings to the Trailblazer if they decided to just stay friends in part one. But for the current version, they just stay friends throughout the whole story.

Imbibitor Lunae Ending
Whereas the romance route is divided into two different endings with slightly different tones. If you enjoy Dan Heng's Imbibitor Lunae form, make sure you say "Alright, it's a date" to show Dan Heng you're interested in being a couple. And then later, when Dan Heng asks the Trailblazer what they think about his past, make sure to respond with "Dragons are cool". This will result in the Trailblazer admitting they find Imbibitor Lunae attractive and Dan Heng will make a mental note of this for later. This ending is a little more on the steamier, romantic side.

Cold Dragon Young Ending
If you want the more comical and playful romance ending, once again make sure you say "Alright, it's a date" to show Dan Heng you're interested in being a couple. When Dan Heng asks what they think about his past, make sure to respond with either of the other two options: "It doesn't bother me" or "Stop worrying so much". Doesn't matter which, they'll both lead to this ending.

Hope this helps everyone get to see any and all the endings they want!
Be sure to let me know if you have any issues.
And thank you for continuing to show love for his little fangirl made vn ~ ^o^