Hi @VisibleFilm ,
Firstly, it's not supported to copy a custom form directly by using PowerApps.
Secondly, you could export components and import components.
I suggest you try components.
You could combine many controls and settings that are common in your original form, save them in a component.
And then export it. In your new form, import this component, which could reduce you much time.
To do you , you need to turn this setting on:

After you create your components in your original form , choose export components.
Then in your new form, choose import components.

Then, your components will be copied in the new form. 😀
Here's a doc about how to use component for your reference:
https://powerapps.microsoft.com/en-us/blog/components-available-in-preview/
Best regards,