The Zulus can save 26 different profiles (A-Z), but... it saves ONLY 1 BC table at any given time. (I know, it is kind of stupid, but it is what it is...)
So what does it mean?
It means you can have 26 different zero's with 26 different reticles/color combinations saved, and choose them at any given time via the menu.
BUT...
If you select any of these profiles, in order to be able to use it in conjunction with the LRF to have the scope display the whole reticle or just the <+> (holdover mark) depending on which mode you choose (dial in or holdover) on the POI for the lased range, you MUST upload a BC table that corresponds with that profile. You only have to do it ONCE, as it will be retained until you overwrite it with another BC table.
So this means that:
If you use it on an airgun with one type of ammo at one powersetting, you're all set.
But If you then change ammo (say from a heavy to light pellet or vv), you want to change the profile (since the zero will be different) and you will have to change the BC table too, as the pellet has different weight, BC and thus flight characteristics).
Or if you change the powersetting on a gun but use the same ammo, again you will want to change profile, for the zero is different (or change the zero on you current profile (either works)) but you still want to change your BC table, as the different power will give a totally different pellet drop.
If you put the scope on a different gun altogether, again change profile, and change BC table.
Every time you neeed to change the BC table, you need do this via the phone app. I think this is an oversight in designing the software, as it should have more than enough memory to store multiple BC tables. (each table is nothing more than a simple spreadsheet of a few kBytes) (and the Zulus could even use the sdcard should there be not enough onboard storage capability) But maybe a future update will change it.