The Infinite Speed user can move any/infinite distance in 0 time, so they can cross the finish line as soon as they think to do so & are able to move.
The Immeasurable Speed user is (typically) "immeasurable" because they remove time from our equation by being able to move to any point in time, &;/or along time. If Speed is Distance / Time, how do we measure it when Time is a negative value, or absent from parts of time because they skipped over those parts?
As such, The Immeasurable Speed user can cross the finish line as soon as they think to do so & are able to move, but unlike the Infinite Speed user -Who we can know the starting point of- The Immeasurable Speed user could, in theory, initiate from any point, even if we thought they started at coordinates 0,0 & 0 seconds; Time is just another axis for them to move along, & they can travel retroactively, or in 1 or more futures we haven't experienced yet.
The Omnipresent user is at the starting line, the finish line, & every point in between. (& since it's spatiotemporal omnipresence, every time in between.) As soon as they think to do so & are able to move, they can "cross" the finish line.
The Immeasurable Speed user could go to any point in the timeline, in theory, but if time travel is like movement for them, that'd mean precision of movement along the temporal axis.
As in, if the race, for us, begins at 0 seconds, but in actuality, begins at 0.0000000001 seconds, the Immeasurable Speed user has to find the earliest possible point where the race has started, which might require finagling their temporal axis movement for a precise position along the timeline.
Sure, they can be at the finish line practically any time, but again, we don't know how precisely they can move.
I suppose in theory, it could also just be waiting to perceive the signal the race has started.
But the important part is they have to measurably (Lol.) start when the race does while finishing before the others, so that they can be recorded winning, which might be tricky getting into the right time, & then get to a time before the others arrive.
It's just that, as long as we only observe the race from our 1 timeline, in a linear view of time, we don't know how much finagling of their temporal position the Immeasurable Speed user did, because they can do so retroactively, by being in the past, which we aren't experiencing anymore, or the future, which we aren't experiencing yet.
Similar issues happen for the Infinite Speed user, except they can't move through 1 or more temporal axes; If they miss the precise timing to start, they didn't start as early as possible, though they can finish as quickly as they like. (IDK who finishes first with different starting times but if both are Infinite Speed.)
But that's the issue. They can finish as fast as they want. In theory, this should cap at actual 0 time, but the Immeasurable Speed user could finish in negative time, if not for having to wait for the race to start.
The Omnipresent Speed user, however, in this case has temporal omnipresence, so they don't have to fiddle with their temporal position, & can just always be at the earliest possible starting time & earliest possible finishing time, no fiddling needed, including "negative" time, Like before the race starts or before the Omnipresent Speed user or any of them decided to start moving.
They only have to start moving. (& assuming they're omnipresent across possibilites, they will, even if in different timelines.)
So in summary:
The Infinite Speed user can finish as fast as they want, but since time progresses for them linearly & they're not able to move through it, when they think to start matters most for them than the other two. If they have to wait for the race to start, precision of thinking/deciding when to start matters a lot more.
Also, only finishing in 0 time, lol.
The Immeasurable Speed user can finish in negative time, as well as go into the past or future that The Infinite Speed user doesn't experience (They're in the present.), but since Immeasurable means being Immeasurable because Time (Or Distance, in theory, I guess?) don't factor into their travel (They can move along at least 1 temporal axis.) we don't know how much "time"/effort The Immeasurable Speed user spent getting into the perfect starting &/or finishing positions. Precision's a pain. Plus, they're kind of hindered by needing to be measured in the race, which is tricky when you may not be in the present, or the right timeline. (& also, the timing of thinking/deciding to start.)
The Omnipresent User, being Temporally Omnipresent, is in every starting, progressing, & finishing point & timeline, so they don't have to worry about precision; They're already at the ideal points, they only need to think/decide to start, assuming you need to be in motion to "cross the finish line".
thx 
