Hi, for guest-gifting there are 2 options:
1) Create an invite-only GA and share a link with one of mods, better if this would happen in Discord (first we would need to connect on Steam). So that a mod would put the link to GA inside the Steam group topic. Problem is, some people probably don't get notifications even though we asked to subscribe to the special GA topic.
2) Join the group by yourself as a gifter and create giveaways for the group normally. All rules will apply for anyone who joins the giveaway that is shared with our group. Problem for you will be that while you are not a full member, you can not join any giveaways shared through PM group. If you see that you could join the GA through another group, you would have to temporarily leave the group and inform mods about this. Later you can re-enter with the help of the mod you contacted. You see this is a simpler option with more reach towards PM members but it is less convenient for yourself.

What seems better for you?

Also, your application to PM is ongoing. I will still need to wait for other mods response in any case so member/gifter applications would be discussed at that time.