Asynchronous I2S FIFO project, an ultimate weapon to fight the jitter

hi guys, I just ordered an rpi 5 and audiophilediyers r2r hat dac.. I was thinking of using ian's fifopima 1.5 reclocker board instead of flagship q7 reclocker because it can work with just a 5V input to power itself and the rpi and doesn't require 3.3V so I wouldn't have to buy a purepi power supply, I could just use my existing 5V linear power supply box.. does it come with standoffs and how do I know what height standoffs I should get to put the r2r hat dac on top if it? 12mm? I apologize if these are dumb questions. please take mercy on me and help me out :D