On 5/30, Volo posted yet another message and image to his Twitter...
I am at the portal now! And this is what I've found... #NoStoneUnturned - @Glovers_Travels, 5/30 @ 8:17PM
It appears as though the manner in which I order these glyphs will determine where I end up. I feel like there's one more piece of information we have yet to receive. - @Glovers_Travels, 5/30 @ 8:55PM
Starting from the top position and going clockwise, the wheel spells out the words "PLANE SHIFT".
Adam Koebel (D&D streamer), shortly thereafter posted a Tweet with three other images (images provided further down), presumably from the would-be Khalesh Marivaldi that has been possessing him:
my computer weirdness seems to continue - every time I export a photo it has this weird watermark and the filenames are always #nostoneunturned - @skinnyghost, 5/30 @ 9:16PM
Apparently while I was streaming I sent this to everyone in my address book, too. Fantastic. What’s going on?! #nostoneunturned - @skinnyghost, 5/30 @ 9:19PMLater in the day, the Immprtal Fortress Twitter account - that of the Khalesh Marivaldi in the Twitter world - posted a tweet with a different path:
I am Kalesh Marivaldi; In that claim I’ve never wavered. Yet the words of this imposter have seen mine fall out of favor. #NoStoneUnturned
I am oft in old El’s Tower, know the spells that keep it safe. And that Volothamp and I had chance to meet within those walls seems now, at least, the work of the unerring hand of fate.
All I’ve said so far is true, and pray my vindication’s swift. The efforts of you Earthers have been nothing but a gift.
The spell to send my dearest Volo home is now in hand; A final glyph determines where in Faerûn he will land. Before this all began I was entrusted with said glyph; Elminster somehow knew that it would all come down to this. #NoStoneUnturned - @immortal4tress, 5/30 @ 9:53PM
This faux Kalesh that condemns me - whether he, she, it or they – has up till now refrained from leading all of us astray. A different glyph has surfaced, through their vessel on your world, and now I fear the depths of their deceit have been unfurled.
Now, on this road we walk, true trust remains in short supply. And when it comes to trust, none know its pitfalls more than I. One glyph sends him to safety, and the other leads to ruin; The path that Volo follows, in the end, comes down to you. #NoStoneUnturned
The Images - Adam Koebel Edit
Three images were provided by Adam Koebel:
It may or may not be relevant, but the third location has been identified as being just outside Manley's Tavern in Cresent Lake, Oregon.
When the watermark is placed over the letter wheel provided, it spells out the letters "PATHINSEF":
The Images - Immortal Fortress Edit
Taking the image provided by the Immortal Fortress Twitter account and superimposing it on the wheel, we get "HASELFPINT":
There doesn't appear to be an actual "solution" to the above, but it does appear to lead directly to the Endgame.