Currently, when you have a Studio Project open, and you install a new Font on your machine, it will not be detected within Studio without first restarting the application.

See attached video.

Repro Steps:

1) Download, without installing, any font from https://fonts.google.com/ (pick one that you know you don't have on your machine already)

2) Create a new Studio Project featuring a MainPage.xaml

3) Introduce a TextBlock to the root of MainPage.xaml, and in its Properties Panel under the 'Font Family' Property, search for the name of the font downloaded in Step 1).
Observe how the Font does not appear, as expected.

4) Install the font downloaded in Step 1), by navigating to C:\Windows\Fonts, and drag-and-dropping the Font's .TTF file inside of the 'Fonts' Folder.

5) Return to Studio, select the TextBlock, and search for the newly-installed Font by name in the Font Family Property.
Observe how the Font does not appear.

6) Save all open documents, and restart the Studio application entirely.

7) Select the TextBlock again, and in its Properties Panel's 'Font Family' field, search for the Font installed in Step 4).
Observe how the Font appears in the Font Family listing, as expected.

Expected Results: Noesis Studio watches the C:\Windows\Fonts folder and is able to display newly-installed Fonts as soon as they are installed.