EDIT: 2s self-timer is a one shot mode, you'll need to press the button every time you want a photo
I tried remote releases with both my 6D and 80D. On burst mode, I get full-speed multiple shooting. Any other mode gets only one-shot per press (or hold) of the remote button.
If you get a TC-80N3, you can use the intervalometer function (ONE-SHOT MODE) to set up whatever parameters you want. Say, take a photo every 3 seconds for 100 photos, or take a photo every 10 minutes for 24 hours, or whatever you want.
This function was not native to Canon cameras until the 7D2, 80D, 5D4, and (maybe, probably) 1DX2. B&H sells a Vello version of the TC-80N3 for about $50.