Added a pressure gauge, pump dimmer switch, upgraded steam wand, and sawed off portafilter to my cheap DeLonghi a while ago. Works good enough and definitely learned a lot about how espresso machines work. Let me know if you’d be interested in a guide on how to perform the pressure gauge dimmer switch mod.
Just remember that o rings don’t last forever, especially if you didn’t use a torque wrench. The ouchie boom potential here is non-zero.
Edit: consider putting some kind of shroud over your various external joints to reduce risk and redirect the ouchie down towards the table away from your face/walls/ceiling.