You can move it, but also install a second one in the other direction. These are "collar ties" (a variant of a "rafter tie"), and their primary purpose is to prevent spreading of the walls and roof due to load and settling. The front beam of the loft storage area is also a rafter tie, and you don't want to leave too long of a span between it and this tie. Right now you have no more than 8 feet unsupported, so strive to maintain that.
You could put the one near the loft up a bit higher, say at the rafter joint, if it's in conjunction with a lower one in the new location. I have confidence that the two together would maintain the integrity of the roof.
Incidentally, the block we see under the tie does nothing. It's maybe there in case you decide to install a pullup bar in your shed, as a liability protection for the manufacturer. Also, you don't need to double the tie. They're in tension, so adding more lumber does nothing. Just fasten them well, with say four 3" screws at each junction.
You could also run two boards from the rafter bottom at the wall plate to the center of the level top rafter chord at the existing location to gain headroom. If you fasten them well, say with lag screws, they'll do the same job as the level tie.
Another option would be to install plywood gussets on all the rafter joints. This would make them into single rigid structures, eliminating the need for ties altogether. Triangles with a center depth of say 12" and a length of about 32", screwed and glued well, would easily carry the roof of this small shed.
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