I’ll let Frankie_V and others continue the deeper programming discussion :), but I can add a comment on the stand to walk/jog/run transition animations.
Originally in these transition animations he took two or three steps past the first step into the cycle, so anyone had the full motion to use or alter as they see fit. UE4 has simple tools to truncate frames from the beginning or end of an animation, so the end user could trim where they want or use the whole thing. After getting feedback and requests we trimmed them all to the first right foot up step matching the phase of all the loops so they would be more plug-n-play so to speak. There are minor differences of the exact posture, arm/leg position, etc. in this slice of time at the end of the transition compared to the posture etc. of the edited perfect walk cycle. With additional animation work the poses could be matched exactly (like all the standing and crouching stationary animations have been), but even if the pose matches perfectly there is still typically a noticeable “pop” between the two as the velocity(speed and direction) of the hips and arms/legs are still slightly different from the cycle. More animation work can fix this of course by manually editing curves or non-linear editing to blend into the cycle, blah blah blah
Bottom line, all the additional animation work can be time consuming and ultimately an unnecessary moot point as blending can take care of these minor differences in real-time, easing in and out of the transitions as Frankie_V put it. A lot of the time the engine will do a better looking job in context on the fly than a hand animated fix.
Similar thing with the cycle to stop motions. The full length original animations are included, but also Left and Right foot up truncated versions. Player input could tell him to stop at any point in the cycle, so the engine can pick the left or right foot up animation depending on which is a closer match at the moment and blend from there to smooth the transition. Run to stops are a definite compromise as in real life (and the full animations) a person doesn’t stop on a dime, it takes several steps and leaning back to slow down without falling over. Depending on how responsive game play is designed to be you could leave in the long realistic “whoooaaa” travel to stop, or cut it short with more needed blending so he stops more abruptly.
Long answer to short question, thought I’d address that. A long time a go we were getting a hard time on “another engine” store saying we need to stop wasting time and their money pose matching or looping anything as the engine could blend “everything”. We didn’t think that was a the best idea. 