Nurse's Matchbox addon + Agitation makes her faster than 115 killers
Performed 3 tests on Rotten Fields, walking from one end of the map to another:
- Nurse w/ Matchbox+Agitation, carrying survivor: ~25 seconds
- Nurse w/ Agitation, carrying survivor: ~29 seconds
- Trapper, NOT carrying survivor: ~27 seconds
My guess is that the modifier on movement speed when carrying a survivor was not changed when the movement speed from the Matchbox addon was increased from 105 to 110%. That, or the modifier has never been correct, and it's using the modifier of Nurse's base movement speed.
Either way, this makes backpack builds with this addon extremely scary, as she can walk significantly faster than a survivor while carrying someone.
Comments
It might be the case that Matchbox is buffing Nurse's speed by 13.75% (+0.55) to reach 110%, rather than setting her walking movement to 4.4 m/s without affecting anything else.
The game uses 4.0 m/s as the 100% reference point for movement. If I understand correctly, buffs are added together and then calculated against relative percentage, not against the value they're modifying. 13.75% + 18% from Agitation = 31.75%. Carrying speed of 92% + 31.75% is 123.75%. Compared to 4.0 m/s as 100%, that's 4.95 m/s.
That lines up pretty well with your results.