I used a basic sample i found on stackblitz and tried to make it work for me but ran into several issues. A major one is that any angular material control on the page i am showing does not work correctly. Below find a copy of the modified stackblitz

https://stackblitz.com/edit/ignite-ui-overlay?embed=1&file=src/app/overlay-main-1/overlay-main-sample-1.component.ts

Here is the complete list of issues i see..

a) why does none of the controls i use on that form work correctly like when i click on calendar it does not show nor does it when i go and enter text in relationship box, it does not show the list. Or even the basic dropdown does not show.

b) how can I specify the size of the Overlay so it has either x% of page or a width  ?   

c) How can i make it that if the form in the overlay is larger then the overlay that it will show scroll bars ?

I included amodal version of the form so you can see what i mean with the calander etc not working in the overlay mode.