Need some insight on TB-500

Regarding TB-500, I understand that it is the 17-23 amino acid fragment of Thymosin Beta 4 (TB4). I see that the common consensus is that TB4 has a shorter half-life requiring more frequent dosing, and that TB-500 affects a smaller portion of pathways like actin, angiogenesis, etc. But does TB-500 work better in some way than TB4? Is there any reason to take TB-500 over TB4, disregarding dosing protocols? If TB-500 is just a fragment of the larger TB4, would TB4 not just be activating the same pathways plus some other stuff on top of it?