Given you know your way around a Mac - you could run a cron job to do the XLD conversion every night. XLD runs from the command line, so it would just be a matter of getting your settings right. If cron jobs scare you, it could perhaps be done in Automator? (I know nothing about Automator though I’ll admit!)
In terms of speed - my collection is most 16/44.1 FLAC, and on a 2yr old MacBook it converts at ~20x. So 3-4 minutes per album.
As for my travel setup - the simplest version is a Dragonfly Red and Final E5000 IEMs (as per here). If I’m going away for a bit longer and know I’ll have time for hotel-room listening, I’ll pack my Grado’s and a Schiit Fulla 2. And given I’m in Australia most flights are 8+ hours, so I do sometimes run the Schiit off my laptop and use my iPad as a remote while flying. 