Re: Alternatives during powder shortage
H4350 hasn't been a difficult powder to find. I have purchased several pounds of it off the shelf in recent months. In general, it appears to me that the slower powders like H4350, H4831, Retumbo, etc. have been more available than some of the faster stuff. It seems to me that the difficult stuff to find has been powders best suited to .223 and .308. Varget is an excellent example of this.
A good alternative to H4350 is RL-17. I have used that myself to good effect. I have lately seen some Hybrid 100V in stock at some online retailers. It, too, is in the 4350 burn rate range. Another alternative is H414.
Overall, I would advise that you are better off just being patient and keeping an eye on the shelves of your local reloading supply stores. Buy what you can when you can.