Good files/packs for practicing gluts?

i’m pretty decent in most skillsets so far, and am able to do upwards of 24-25 files in most skillsets, however I feel that i’ve fallen super behind on my jacks, more specifically my gluts/longjacks. Are there any packs out there that would be helpful to work on them, or files from packs like SMOC that you think i should play in order to help me improve at them?