US ICCU Recall (aka 12V battery failure issue) and Tesla Supercharger access and adapters. Please do not create duplicate threads on these topics. Links: ICCU Thread | Supercharger Thread | Adapter Thread
DIY would be some of the mechanical work such as brake job, suspension, steering component, differential fluid change or any retrofit works on Ioniq 5. Since ours is an EV, no need to worry about, engine oil change, transmission oil change, coolant change if any....
You most certainly do need to worry about coolant, how do you think the traction battery temperature is controlled? Also, have a deeper dive into the maintenance required for the motor(s).