I asked you over Input current, how much is it, are the LED resistores/impedances in range of data sheet?
The ca. 5usec Tsw is specified with in/out currents of 1mA! Check for fig. 8 pls...
For 117VAC their proposed 180K+ 22nF/200V combination or ohmic 285KOhm in part of LED!
I have had read somewhere, that (photo)transistors can be speeder switch if BE has a Schottky (Cathode at B) on(this is a knowed effect)..
Your switching time must be independent of schmitt trigger as load!, but more depend of the input part_why do you need the 100nF on the bridge?
I dont understand why you have it, if you are free of these "filter" your opto koppler wil, or can, follow the input half sinuses and that is what you need_I think!? If you need smaller/shorter output pulses as the halfwave(8.3ms) you must differenciat it befor connected to the schmitt (Highpass R-C filter)...
K.
Sorry I overflyed the input current of 7-10 mA...
I dont know how these component swithching time changes with higher Input current_but i think, that your factor of ca. 1000 is not from that, but more from the input filtering 100nF. I think you must verify it_is it (more as 1mA Led current) relevant by these copplers switching times or not?