Hi @DrWino,
I tried my sample project I was able to read and write a Mifare Ultralight EV1 Tag.
I think that in your smartphone is set to use always a specific app when you approach a Tag this is the reason my sample doesn't work correctly, to override this problem the extension should have the tech list and manage the intent. But I was not able to add this features in the extension.
Here I wrote about this problem