Using Teensy4.0 instead of Teensy3.2

I made a large (2’x5’) display using a Teensy3.2 with logic for driving the matrix based on the SmartMatrix 3.0 shield. (I bought one but cloned the logic parts, using TTL DIPS). It worked WELL.

Now I have to use a Teensy4.0 since I have no substitute 3.2s available (and PJRC says we have to wait until 2023 to get them).
How should I proceed? I have the schematic for a 4.0 to 3.2 adapter board, and also the 4.0 SmartMatrix Shield. Which one do you guys think is quickest and easiest? I’ve made converter dongles before (I used wire-wrap…quick and dirty for prototypes), so not a problem going either way, I just don’t know which I should spend my time with.

An adapter has been designed that should allow you to directly plug in the T4.0 into the old shield. You can get it fabricated at Take a look here:
Teensy 4.0 Released - #32 by Louis