Thanks you for the devlog, and nice to see I did not chosed also a Dungeon Master like (this was one my ideas)
Just a small remark
- adjust hpos and vpos accordingly : +width if you HFLIP, +height if you VFLIP
You can define the action point of the sprite and this impact the FLIP (and also TILT & STRETCH)
For example, if you have a 17x17 sprite and define action point in the middle at (9,9), flipping horizontally or vertically will not require to adjust coordinates.
But as you use TILT & STRETCH also, it may imply some side effects...