If you stray even a few millimeters off the official Magic card size, it can result in disqualification at sanctioned events or suspicion of cheating
The only potential problem is that you do have to tap out, so if there's a strange combination deck that can discard three cards, sacrifice a creature, and go off anyway, then you'd have to be careful
The most expensive Unfinity shock lands are: Hallowed Fountain, Watery Grave, Godless Shrine, Steam Vents, and Blood Crypt
Buying one copy of every set legal in Pioneer would only cost you $6,546, which means you could buy a playset of every single card legal in the format for $26,184, leaving you with more than $5,000 left over compared to buying once of every version of every card printed in 2020
I know Id enjoy the strategic complexity of playing Magic, but its just too big, too old, too intimidating