The ATO you have is more of an "all in one" solution. Aside from using the power-monitoring to map it's draw (and that only if you have the new Apex, of course), I don't really think I'd try to mess with the outlet, myself...
The ATO has two sensors - a low on for "on" and a high one for "off"; if you've got these placed correctly, the pump should only run for the time needed to keep the tank at the proper level. The further apart the sensors are, the more swing you'll get, but the less often the pump will come on (and thus it's service life will generally extend). So you "tune" the ATO by how far apart in depth the sensors are set in the tank.
It would be highly uncommon for your evaporation rate to be the same throughout a 24hr period, which means that your top-off rate won't be the same throughout. That's why pretty much every ATO worth it's cost uses a two-sensor setup to control the on/off cycle of the pump.
Basically; the "OSC" command you have is you trying to manually override the "smartness" of the ATO. If that is your goal (and it's your tank so your goals matter more than anyone else's), then yes - you would get a "20 seconds on at the start of every hour" from that line. You mentioned that you don't have a low-level sensor in your ATO container, so where is the "Swx4_6" sensor located?
The PH check is something I've seen before, but I've always felt it to be undesirable. Turning off the ATO when PH rises may very well compound any tank issues (a salinity rise on top of a PH spike). There are certainly arguments as to why it's good to have such a check in there (and I don't really have good counters to those if/when they are raised), but for me personally; I prefer my tools to do one thing - and an ATO is for controlling salinity in my tanks.
