I know there is a known issue regarding rounding down the coordinate when inputting an MGRS coordinate that lies exactly on a grid's corner (Military Tools for ArcGIS 3.6.1—Military Tools for ArcGIS resources | ArcGIS Solutions for Defense)
Has this issue been resolved in version 100.8 that was released May 7 2020?
Hi Nicholas Liccini,
It's unclear that the issue you referenced with Military Tools for ArcGIS would manifest in ArcGIS Runtime. Since that tool is not specific to ArcGIS Runtime, you can probably get an answer over here to see if it is fixed.
I hope this helps.