I'm sure it's possible. I know
@MtnViewRanch sells them and welds them as needed. I've seen pictures he shared where he retained the extendable arms while using the hooks.
In my opinion, and having used the hooks, I see no point on retaining the extendable arm feature. The way you use this, is to back to an implement, with the hooks sitting lower than the pins and balls on the attachment, once the hooks are in the right spot, lift the arms and you're good to go.
However, if I were adapting the hooks to a tractor with extendable arms, I can see how it would make sense to retain that feature since it helps mounting the hooks on those arms.