Hi.
Trying to remember how this goes. I make the 3 FP selections for Epcot or HS, use my first as a Tier 1 and then cancel the others, right? Then what? Since I’ve already used one, I can’t make another 3, so I assume it will be just one at a time at a kiosk and the next one needs to be the second Tier 1 that I want. Is this correct?
Yep. I think that is the correct theory. I did not do the cancel method but I did use my first three by moving them up each time I used one. Then was able to book a 4th for Test Track.
Example (Times are approximate for illustration only) 
I had 10:00 am for Soaring. At 10:15 after I had scanned both times in the fast pass line, I moved my 11 am fast pass to 10:30. Then at 10:40 when I scanned my second FP selection both times, I moved my third up to 10:50. At 11 when I used my third FP, I rushed over to book my 4th and was able to get Test Track Tier 1. We were able to get and use a total of 5 FP that day. Two being Tier 1. We could have got more but we stopped for margaritas and dinner. Priorities, ya know!
Belated thanks AuntB! I will try this in June!