Only seeing one quest marker at a time is a drag and interrupts the flow of the game. It would be much better to be able to track multiple quests at once so it's easier to see if any objectives are nearby.

Absolutely agree. The number of times I turned in a quest only to realise I could have managed a couple more on my trek back to town...

Big must, the time lost because of this is incredible.

Agreed. I know you can short quests by locations, maybe an option to toggle "all questions by location" work with a "primary quest marker" being green and other quests having a customized color (yellow? Blue?) so that the "objective markers" don't get confusing.  Example: I had a few quests on Scylla, while exploring I came across the medicine delivery and I was excited that I found a new quest before I realized I already had it listed in my journal previously. 

Just a nice quality of life tweak.