The release rate difference between IM and Sub-Q is not significant as it pertains to these peptides.
Method of action is agonism of the Pituitary Somatotrophs, thus these secretagogues need to go systemic to get there.
You could do either IM or Sub-Q to acheive this, but since no specific "local" effect is characteristic to these peptides, IM is not necessary.
Take Care.
PS- There have been long debates on IM vs. Sub-q for Humulin. One side said that IM will cause it to be utilized more quickly and be out of the system in 3 hours (instead of the normal 4+ hours or so) This was welcome for ppl that could not get fast acting Humulog. After much research it seems the conclusion along withsome date I saw somewhere showed that it makes no real difference, both methods have equal clearing rates, thus this injection style does not make much impact on release differences.