I was reading up on sendmany. Does it have to be done from Bitcoin Core, or could it be done from a GUI type wallet, and if so, where is it!?
For the record... Bitcoin Core does have a GUI... and it's easy to do "sendmany" in the GUI... you simply click the "add recipient" button:

Obviously, not as easy as creating the CSV file and bulk importing 100+ payments into Electrum

, but if you already have Bitcoin Core and you're wanting to make multiple payments in one transaction, it is quite simple and easy.