In hopes of helping others avoid the frustration I have encountered with the valueat() function, I’ve put together a simple model illustrating the bugs and/or design flaws that I have come across while attempting to use the valueat() function. Long story short, I’ve found valueat() to be unusable in anything but the most simplistic models.
If you use Timelines with multiple categories, or if you use summary items, you can forget about using valueat() at all.
I really hope valueat() can be reimplemented and improved soon; this is by far my #1 pain point with Quantrix. I have resorted to generating my own position counts (instead of using #), and using select functions to perform the offset work. That makes my model much more tedious to maintain and harder to read.
If anybody has come up with better alternatives or solutions, I would love to hear them!