I still think scaling is an issue on the Quest - the software part of the IPD adjust doesn't seem to work properly, resulting in a smaller world scale.
Yup. Its clearly not 100% optimised yet but I think they have room for improvement. The world scale shouldn't be difficult to work out. They have a tiny bit room for a clarity boost and then I think they need to work on increasing the vibrancy of the colours as they're not taking full advance of the OLED panels.
Carmack mentioned long term wise they could potentially exponentially increase the quality of the Quest via Link but it'd take a lot of time and work with hardware people.