Display user's name instead of username For various compatibility reasons, I would like my usernames to be standard no-spaces combinations, so jbloggs / jdoe / etc. This becomes unsightly when displaying blogs ("jdoe's blog") or node authorship ("15/09/2016 jbloggs").

I've added first/last name fields to the account, but can't find a way to have them displayed by default instead of the username. I am on Drupal 8, so Profile2 isn't yet ready, which means this answer isn't an option. Likewise, this answer proposes using the "Real Name" module, which doesn't have a D8 version.

If it's any help, I would basically like the full name used in every display context, so if there's a blanket solution that would do that, rather than giving me control by node-type, that would be more than acceptable.

Lastly, if the above isn't possible without a module, can someone point me to some info on referencing account/profile fields in twig? That way I could at least override it in the most prominent places using templates.
I'd add a new field called Display Name (or similar), then then use hook__user_format_name_alter() to load in that field, and change the display name to use the field value instead of the user name.

Here's the change record for D7 -> D8, where it used to be hook_username_alter(): https://www.drupal.org/node/1408514