Stepping up is unreliable
When attempting to climb a square obstacle tall enough that jump height is insufficient and a step up is also required, from a position directly adjacent the obstacle such that horizontal speed is close to zero, the player will often fail to make the jump (pressing +forward and +jump and looking directly at it). When starting from further back (run up), the player will succeed in mounting the obstacle. Attempting to strafe jump at the obstacle also increases the chance of success.
On q3df map pornstar-goethe are small stairs the player can climb at very high speed (many step ups per frame). Sometimes the player comes to a dead stop on these stairs, and it's not always at the same position. I think this is the same bug as above.
Although this affects all maps, fixing it is necessary for fully supporting Q3 maps, as Q3 does not have this problem, hence the milestone.
Self assigned because I'm testing a potential fix.