Question about beastmorph alchemist

[about50heavies]

when it says for Beastform mutagen take x abilities from alter self/beast shape spell is the ability score increase from a certain size create available to use?

[StreamOfTheSky]

I don't think that was intended. As for RAW, I have no idea, the entire entry is poorly worded (strict RAW, you'd keep stacking the # of abilities you gain w/ each improvement, instead of overlapping/replacing, for example...despite that definitely not being the intent). You should just ask your DM. If he'll allow it, good for you. If not, he probably wouldn't care if it's RAW or not anyway.