I'm the parent and yes like the other reply here I do the same. I keep a bouncer (Quassel in my case) connected 24/7 on a VPS.

Quassel is really nice, it's got infinite scrollback, multi-network, GUI configuration that is stored on the server, logs go into a database, and the desktop and mobile clients (QuasselDroid!) are really good. It brings IRC into this century without giving up what makes it so good. Unlike Matrix which is aiming more at the Whatsapp/Telegram/Discord community.

I use both mind you, but I don't integrate IRC into Matrix for this reason. I use Matrix just for the individual and small group chats and Quassel for IRC. Matrix gets too messy when you're on tens of different group chats.

Yes, you just stay connected for a long time (idling). I run a bouncer (forward proxy for IRC, basically) on a server so I effectively stay connected 24/7 to all the channels I'm in, so asking a question, waiting a few minutes to see if someone answers immediately, and then leaving and coming back an hour or two later is totally normal (you could of course just keep your client connected, but my internet's not quite that reliable).