The oring should help muffle the sound. It shouldn't have anything to do with the actuation point unless it's something that 'feels' like the actuation happens sooner. What commonly happens with many keyboards, the key reaches the actuation point which may only be 50-60% of the key's travel until it bottoms out. It can be difficult to halt the press of a key partway down so the tendency is to press until the key stops. That's not where the keypress is recorded though, that part of it is built into the switch itself.
If you frequently bottom out the keys then it could help give you the impression of a shorter key stroke since you'll bottom out just a tad sooner but the actuation in reality will remain the same.