For anyone encountering the same issue I’ve got it figured out
In the User Blueprints folder Put them in
user/blueprints/pages/. This is a good place to put them when you simply want your blueprints to be present in your site.
In the Theme Put them in user/themes/YOURTHEME/blueprints/.
This is best when you also intend to distribute your theme: the theme will provide the page blueprints and it will be easier to use.
When creating blueprints in a theme, IF the pages directory is exists (even if empty), the modular blueprints must be nested in the pages directory. Else they can be in the blueprints/modular directory .
The following two will not work:
├── blueprints
│ ├── modular
│ │ └── heading.yaml
│ └── pages
│ └── modular.yaml
├── blueprints
│ ├── modular
│ │ └── heading.yaml
│ ├── modular.yaml
│ └── pages <==== The directory still exists
The following two Will work
├── blueprints
│ └── pages
│ ├── modular
│ │ └── heading.yaml
│ └── modular.yaml
├── blueprints
│ ├── modular
│ │ └── heading.yaml
│ └── modular.yaml