So, after much experimenting with dreamcast on the XU4 I have come to the conclusion that performance is much better via the android app than here on Recalbox.
However, that is only true when enabling the option for "Synchronous Rendering" within the android app. This can be enabled on the Linux version here on recalbox via the emu.cfg file within the reicast directory.
Unfortunately this file is overwritten as part of the reicast startup script, and I am having much difficulty editing this script as it is set to "read only" and I have tried just about everything to make a number of directories on recalbox r/w with no success.
Bottom line, can someone launch reicast with "Synchronous Rendering" set to "1" and check for this performance increase here on recalbox. Also, how can I set my entire /root directory to r/w? I can't seem to find a solution.