Trick is to make a bit larger instance, then scale it down to the always free limits - or so I've heard. You might pay a small amount, but totally worth it. That Arm server with 4 oCPU, 24GB, 200GB SSD is a beast, I've had it since 2022.
Btw make sure you crank up the SSD speed all the way, as long as it is in the always free limit, you won't be charged for it ... Even though it says you will.
i've attempted signing up for this thing like multiple times over the years and i've never had luck trying to game their free tier. based on all the other comments it sounds like you're SOL at this point none available or people on 4/24 are getting downgraded. maybe i'll try again sometime but i haven't seen any recent success stories