Hm-mh.

What I'd recommend is using the Hayward Super pump (which you'll need to run your Pulsar feeder!) to fill the portable. You can run the Hayward off a single 15A receptacle, with a 12 gauge 50' extension cord. You can use the dichlor during the fill period to keep the water chlorinated . . . and you'll have the CYA level you need, when you're done.

How far from the main pool, is the outdoor pool? Unless it's a really long way, you'll probably need a ball valve in the pump outlet, to allow you to introduce some flow resistance -- if you allow the pump to run wide open, with little resistance (2" pipe, no filter, no heater, etc.) you'll either (a) trip the outlet breaker OR (b) burn up the pump motor. If you get a Hayward SP2605X7 3/4 uprate, you should be able to run 50 gpm without overloading. That will allow you to fill in 32 hours.

It looks like your August typicals are 60/90, with lots of sun. Under those conditions maintaining temps above 79 shouldn't be a problem, unless you get LOT of wind at night. So, filling from the main pool likely would allow you to skip the heater. Certainly, one small heater would be enough to maintain the temps. You could actually run the heater AND the Pulsar off the SuperPump, allowing to avoid screwing up the hydraulics of the primary pumps.

Check with your electrician. It may be possible to install the SuperPump on the outdoor pool that way, too. I think you'll have to use a 20A locking receptable and matching plug, but that's not a big deal. You'd then need an adapter extension cord, with a standard 15 mail plug and an added 20A female, so you could use the completed pump temporarily to fill the pool, and then immediately move it into service on the pool itself.

By the way, you should check both FC and CC on your fill water -- you may be holding a higher monochloramine residual. If so, you'll need to plan to super-chlorinate to remove those residuals BEFORE swimmers get into the pool -- mono-chlor is pretty nasty on eyes. If you do have a significant chloramine residual, allow yourself 48 hours to clear it. Of course, if you use main pool water to fill, that may be another problem you'll avoid, since you have that UV reactor inline.