Definitely finish slamming first! Its actually not possible to correctly follow both a slam and AA treatments simultaneously, so read up a bit on that.
Have you confirmed, using a crushed up vitamin c tablet, that the stains are metal and not organic? (If they're organic, they will fade with sun, adequate maintenance chlorine, and time.)
AA treatment requires low chlorine level, and there's a risk of outbreak at such low levels...which is why the addition of polyquat is recommended prior. AA also fights chlorine (chlorine eventually oxidizes any leftover) and you have to carefully bring the FC back up when finished to avoid having the stains come back.
Before you start any stain treatment, tell us a bit more about what kind of stain you think it is, if you're on well water, where the stains came from, etc. and any reading on metal levels you may have had.
Kudos on your almost-complete slam! I'm sure you're excited to clean up the stains, but truly, take a little pause and make sure you know what you're dealing with
pS - can you please add details about your pool to your signature? Thanks!