If the load fits perfect with the AA-L wad use it.
Bare in mind that the Lee slug is a 1oz design and you can fire it using just about any 1oz load data. The AA-L grey was is rated for a 1oz load so it should not be hard to find the correct data for an AA-L wad in an HS/AA hull for a 1oz load.
I use this technique all the time and have fired hundreds of improvised slugs.
1oz of lead is 1oz of lead be it shot or a slug, as long as everything fits smoothly like with the AA-L wad and you don't get pressure increasing bulges like with the Red wad, you'll be fine.
And yeah, I to find that Red Wads work well in Federal Hulls. For that reason I mostly use the Fed hulls for all my hotter slug and buckshot loads that call for a Red or Yellow wad.
I prefer AA/HS/Universal/Supertarget hulls for 7/8oz light clay loads I make for the girlfriend. I've shot thousands of 1oz loads out of Fed Hulls using a 12S0 wad. That's my go too load for shooting clay, using E3 powder and cheddite primers.
I'm just shooting stuff out here at this point cause I'm experienced with loading using the Load-All 2 and know some tricks to getting perfect crimps with it.
It's a machine you have to go by feel. For instance, when you are pre-crimping, don't just jam the handle down all the way, it will often precrimp deeper then the original crimp shortening the "OAL" of your shell. It will also cause other problems.
When you pre-crimp, feel as you push down, and usually, you can feel the plastic start to resist, that will give you a feel of the hulls natural crimp, then you're good, do not go any further.
You'll figure out what I mean, but once you nail that, you get much better crimps.
Another trick is, if you have a load that consistently crimps poorly, or the hull gets crushed and wrinkled, it's often cause the wad is not properly compressing during the final crimp.
The wad is SUPPOSE to actually crush a bit during the final crimp when your wad column gets compressed and seated together. Higher end presses are dialed in to do this during the final crimp.
The Lee, not so much. Sometimes what you have to do is precompress the wad.
When you are seating the wad just before dropping your shot, push the handle down further to crush its legs. Don't worry, you won't damage the wad, they are designed to do this, normally, as mentioned, during the final crimp.
With the Lee you have to do it for some loads during the wad seating, and this comes up most often when using tall AA wads like the L and SL, most often with AA/HS hulls. The precompression also serves to seat the wad base into the taper.
Do that, the wad will spring back up when you take the pressure off this, and your hulls, also using that feel technique, will crimp way nicer.
Again, I've loaded and shot 1000's of all sorts of different loads using these techniques, and hell, some guys I show my loads to can't tell them from factory.