As you point out 2-73 addresses the AD process much earlier in the disease sequence. If PTI-125 turns out to be good at removing existing Tau and plaque, I can see another drug combination with 2-73.
2-73 would stop the disease process and the PTI-125 would be good at removing the existing accumulations of waste proteins.
That combination would provide the best opportunity for the brain to regenerate as much as it is capable of.