Your body is certainly not in one distinct volume across spacetime
Yes it is shaped roughly like a spikey, 4d worm-like structure with "blobs" occasionally dangling off or around it.
Nor are you equally free across spacetime
Well, before it's shaped like a worm it's shaped kind of like a frayed rope, but much more squiggly, and it looks kind of "melty" at times
In fact, I recently saw an image that sort of looks like what "I" was before I was me, but in 2d frames in 3d, though I'm not sure this is what the intent was to depict... It looked kind of like a tree with vertical branches all extending off into unfurled particles going their own ways?
Then at the end, it progressively gets more confused until things start separating and the bundles that were start being consumed into other stuff and they lines of its cross section stop interacting, and then before you know it, what was all woven tightly drifts promptly apart.
This is in fact one of the reasons you bringing up the Trinity is SO ironic, though, because in addition to that element of me, the spikey worm with frayed ends, "me the child" as it were, there is another "me" more shaped like... Maybe you could represent it like with lines and structures and connections sent into the worm from tufts or "weaves" in tight bundles of stuff outside it, that causes its shape to conform in some way based on what it receives, and other lines extending out back into the more distinct "weaves" of the thing and those connect through and to past instances of other "spikey frayed worms", and they eventually come into and define part of the structure of the spikey worm. This "ghost" connects the whole worm to one or more such "frayed worms" and more bizarre shapes still (the points where bundles become tight weaves rather than diffuse frayed ones).
But some features of that frayed rope's.xross section themselves come to reflect a system which directs where and how the thing is woven together. When the right combination of structural elements (the symmetries of the cross sections of the "woven areas") form some structure among the diffuse connections to the worm, the worm's own weave of bundles shifts to conform to some new cross-sectional conformity.
Across parts of that the structure around this worm various constraints act as hard or soft walls which will prevent the worm from moving past their positions in spacetime, however abstract, owing to controls and lines connecting out, and forward, and into the worm so as to direct it. When these undue influences.
Sometimes the spikey frayed worm merely moves of its own accord, not in connection to another spikey frayed worm but because of something inside that volume.
Depending on whether the motion is due to a wall, even a wall formed of decisions made due to the threat of not achieving some position in the space, or whether that motion is due to the structural rules created inside the spikey 4d worm, we declare the thing "constrained" or "free".
Believe me, I might have spent some time actually thinking what shape I have through spacetime and what observations indicate the freedom and constraint in that shape.
But yes, it is strictly speaking a very strange 4d volume.
If you want I can TRY to draw a 2d version of it that paints it correctly, and extend concepts of area to volumes, and I would have to use spheres or dots to avoid implications of concurrence, or imply some 3d space.
I will admit, though, this is the first time I pushed myself to visualize it completely, so kudos on you for that.
The "human as a frayed spikey worm-rope through time" visualization is in fact one of the ways I've been pushing myself to visualize weirder shit, including block spacetime.
Doing so usually leaves me feeling like my head is full of lead -- which it might be given questionable choices of chewing material as a child -- though "full of piss" is more likely, given how metabolism works.
