Canon's own EX speedlights should all be compatible, if not fully compatible. The official word from Canon on their brochures and websites for the bodies without the sync contact is:
Speedlites other than the EX-series or non-Canon flash units cannot be used. Not all functions of the Canon EX-series flashes are supported.
In April/May 2019, ...
All canon EX speedlites should work.
I have 2000D with the crippled hot-shoe too, and 580EX II and 430EX III-RT both work. The 580EX II is an older speedlite than the camera, so you are not restricted to only speedlites released after the camera was released.
I am also able to trigger both speedlites with ST-E2 optical trigger. I presume the ST-E3-RT radio ...
I have personally pitted screwdrivers on (non-photoflash) electrolytic capacitors that had sat charged but idle for WEEKS.
Self discharge specifications of such capacitors will always be worst-acceptable numbers, since self discharge and leakage currents are usually considered undesirable to an engineer.
Never rely on a big capacitor being safe unless you ...