The Repeater is a bit weird and behaves quite differently compared to the other standard DSP effects.
The key thing here is the Mode parameter.
The Repeater will continue to repeat/retrigger whatever audio was captured when you first turned the effect on by changing the Mode parameter from “Off” to one of the active modes “Free/Even/Triplet/Dotted”.
It will not fully reset the audio buffers until you revert the Mode parameter back to the “Off” state, and then switch it back to one of the active modes, where it will begin to re-capture a new chunk of audio.
The Hold parameter primarily controls how the GUI (the grid cells) behave. When Hold is enabled, you can click on a cell and it will remain active until you click it again to deactivate it. This is handy if you want to trigger a certain timing and then queue up a different timing. When Hold is disabled, you click a grid cell and then the effect will automatically turn itself off when you release the mouse button.
The Hold button was never really intended to be automated. It mainly only affects the mouse behaviour while you’re tweaking the thing in Renoise’s own GUI. The actual behaviour of the Repeater effect itself can be entirely controlled by manually changing the Mode and Divisor parameters.
I thought the same thing a couple years back, and actually made one. I’m linking, since it has some tricks of it’s own - multiple delay lines with ADSR, built-in sequencer etc. Not exactly bug-free though (it has some slight timing issues).
What the device really needs, I think, is the possibility to map the fraction buttons (1/1, 1/2, 1/4T… etc) to MIDI events separately. I’m trying to figure out how to do it with the Divisor, but if it works, it is a pain (maybe with some additional meta-device?).
The 1/2 1/4 1/8… buttons should be selectable and mappable in MIDI Learn Mode.