Try scaling the arms in only one axis, the long one (probably Y) by a moderate amount, rather than the whole arm.  There are morphforms for arm thickness and forearm thickness that you can adjust the other two dimensions with.

V4.1 has a LOT of different face morphs that are worthwhile all by themselves, and I believe a couple of extra morphforms for shoulder thickness and one or two other things.

Bodypart scale changes are hard to make portable imo - my advice is morph as you like, and then note the scale changes and make a separate pose file by hand to set those parts.  Typical INJ pose creator probably won't build it into the pose file (could be mistaken).

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