Does the country provide individual online voter registration/polling assignment checks?

Estonia

Answer

Yes, confirmation of registration using online interface
Yes, assigned polling station using online interface

Comment

Citizens can use the portal to check information about them in the Population Register and receive the electronic voting card with the information as to where, how and when they can vote. The Eesti.ee portal is a part of the EUGO network of EU state portals that provides points of single contact for entrepreneurs throughout the EU.
https://www.eesti.ee/portaal/rrteenus.index
https://www.eesti.ee/portaal/valimised.eabi