I put together an non-comprehensive list of Foundry missions and how much XP I got out of them.
Here's my shitty Neverwinter Foundry Logs:
Foundry Quest and XP Listing
I attempted to log in the best time:xp ratios and per level but really lost interest
I was able to complete Protect The Caravan in 15 minutes last night, getting 3-4 bars each run each time. I mean, I lvled 57-60 in about an hour and a half doing this over and over again. There are alternate paths as well in Protect The Caravan.
If you guys want to add to the spreadsheet, let me know and I'll make it editable. Currently, you can only comment.