No, since refilling my pool (from my re-plaster fiasco) and taking it away from pool guys, and by following TFP religiously, I've never had to SLAM, or even had a hint of green. My pool used to get some algae on the walls (when I used to pay a "pro" for maintenance), so I know the potential is there, but TFP has kept it clear. So I don't have any direct experience on what to do with solar during a SLAM. That said, my uneducated guess: since SLAM levels are safe for humans to swim in, I'm not sure what your concern is about the solar system. Algae shouldn't be growing without light inside pipes and panels, but since clearing your entire system of all algae, and all its nooks and crannies, is important to rid your pool of the green monster for good, I would be running "SLAM water" through everything I could, 24/7, including the solar system. Theoretically, if you don't do it 24/7, then even if there is no algae stuck to insides of the solar components, you'd still be "storing" water that is isolated from the rest of the SLAM process for periods of time. That might be counter productive. Keep all the water in your system circulating throughout the SLAM for maximum effectiveness.
Sidebar: this is anecdotal at best, but it's what I believe. I use Leslie's for chlorine. I have seen first hand how Lowes will stack new chlorine on top of old, so at some point someone is going to get stuck with expired chlorine. Seems like you have a handle on the date codes (when you wrote "60-day old chlorine") but the number of days is not all there is to it. If the pallet of chlorine is improperly stored, anywhere along its trajectory (while in the store, or before it gets there), its effectiveness could be compromised. Like if it had been left out in the sun for a length of time, or stored in a hot warehouse somewhere. Since I've witnessed Lowes' ignorance of chlorine storage first hand, I don't trust what they're doing, or not doing, behind the scenes. My Leslie's assures me that their chlorine is never more than a week or two old (which I suppose may or may not be true, but because it's a small store, they can't be hoarding a large supply like Lowes can). And I know for sure that they store it inside, in a back room, so it's sun exposure is minimal. Their price is competitive, so that is a non-issue. I'd rather be sure of the quality than try to save a few pennies at the big box stores.
That said, you can test both your chlorine's effectiveness, and the volume of your pool, simply by testing for chlorine just before you add it and about an hour later. If the amount you add gets you the expected result, then your chlorine is OK and your pool volume number is accurate. If you add chlorine and don't get the results you should, then either your chlorine is weak, or your pool's volume number is wrong. This only works once the pool is free of algae, of course. But the method can still apply to your SLAM process: keep adding and testing regularly until the SLAM level is achieved. Don't trust amounts added or pool volume numbers, trust only the test kit results.
