I finished the Tank Job (?) quest line for Endwalker. It was interesting how they paired you with one of the realm leaders, and it looks to be a complementary class. For tanks, it was Kan-E-Senna of Gridania, who is basically a White Mage, and it was a nice look into the workings of Gridania.
I also did some of the side quests in Zone 6. One thing about side-quests in Endwalker is that they are very optional this time around. I think the MSQ by itself gives enough XP, and the side-quests scale for the most part.
Personally, I like doing side-quests alongside the MSQ, as they give you a better picture about the zone, and fill out a lot of the small details. This time around, I did most of the quests as a Paladin, which is what I was doing the MSQ as, but I switched to Red Mage right before turning the quest in. I started doing this in about Zone 4, but I wish I had done it a bit earlier. I hit 90 on the Paladin relatively earlier, and probably could have gotten another couple of levels on my Red Mage.
The accessory gear rewards also come in a box, so you can switch back to your main class before opening it.
So for those of you who haven't done Endwalker yet, that's my recommendation:
- Do the side-quests alongside the MSQ,
- Turn in the side-quests as a secondary class. You'll get several levels on that second class.
- Open the rewards as your main class to keep upgrading accessories.
In my opinion, that gives the best combination of story, gear and XP efficiency.