@jeffdi @Tim Edwards Let me know where I can find the MPW-2 caravel netlist & spef. I like to analysis from my end on why OpenSTA tool not reporting any hold issue around the GPIO logic. As per my git analysis on file gpio_control_block.v, the inter block delay cell added on 21 st Mar 2022, Which means around MPW-5 this delay got added.

commit be56cb19edb5ab9aaace5d6f8f2f7fac7e015fbd
Author: Tim Edwards <tim@opencircuitdesign.com>
Date:   Mon Mar 21 12:07:12 2022 -0400

    Modified the GPIO control block to put additional delay on the data
    output of each GPIO block to overcome any wiring delays between
    GPIO blocks that could potentially cause hold violations.