so, it leaves me wondering what the heck the real problem is ! Software or Hardware ???
Well a bit of both. Hardware was designed prior to pipewire being used so there has to be slight differences in the way blank spaces are handled between songs if there is a noticeable time delay without any data.
If you can hear a clicking effect on track change using the IIS connection, a quick and easy solution would be to use an USB cable between the Pi and the EVO board instead of the GPIO I2S since the XMOS USB chip has additional digital pre-filtering to handle this kind of situation.