Hey there daniish,
Hope you’re well today!
Custom Sidebars simply replaces the sidebar on specific page/posts etc. You can still create a sidebar with no widgets in and select it in the Posts -> Edit https://screencast.com/t/AyERjBet, this will add empty sidebar to that specific post.
With that being said, I’ve tested Widget Logic Plugin and I didn’t run into any issues but the result will be the same as using “empty sidebar”. Widgets will not be displayed but the sidebar will still be there.
If you’re looking to remove sidebar completely and make specific post full width I guess that will have to be done with some custom CSS.
Hope this helps ??
Best regards,
Bojan