If you are proxy testing a Zimone Commander build before buying the weirdest stack of Simic cards known to cardboard, ProxyKings MTG proxy shop is the sensible place to start
Effects that switch the creatures power and toughness are always applied after any other power or toughness changing effects, including this one, regardless of the order in which they are created
Before it's ban it was a highly effective tool in high-powered and cEDH decks that often represented too great a mana advantage to be fair at more casual tables
As long as you keep paying , the process continues
Blink Pack #4 | Jumpstart 2022 Creatures (8) 1 Brightmare 1 Cavalry Drillmaster 1 Distinguished Conjurer 1 Inspiring Overseer 1 Pierce Strider 1 Rambunctious Mutt 1 Seller of Songbirds 1 Wispweaver Angel Instants (1) 1 Flicker of Fate Sorceries (1) 1 Settle Beyond Reality Enchantments (1) 1 Faith's Fetters Artifacts (1) 1 Panharmonicon Lands (8) 7 Plains 1 Thriving Heath The final pack might as well be the SaffronOlive special, as while it lacks a copy of Preston, it instead has Panharmonicon
This pairs nicely with two other abilities that The Meathook Massacre has, having your opponents lose one life when one of your creatures dies, and gaining one life when one of their creatures dies