I really like the LFO meta device and find myself using it often.
To expand upon the types of modulation sources, I think it would be really nice and useful and to have an X / Y Pad modulation metadevice that can be assigned to various device parameters and could record their movements on the pad affecting these parameters with the ability to play these movements back, configure loop settings (one shot, loop, ping-pong), adjust speed, amplitude range, and save settings for future use if desired.
Part of this can already be done within renoise (right click slider, CC’s, manual editing of the automation), but this would make it a dedicated device, with the advantage of controlling two parameterss in real time (e.g. cutoff & res), which would be difficult if not nearly impossible to get the same feel out of if done manually.
One could take this further by adding a z axis that could be controlled by the mouse wheel or a midi controller.
Either Way it would be nice to see more meta devices in general, possibly employ an API for third parties to develop them.
Other modulation devices such as a step gate, multistage envelopes, and perhaps something similar to the Galaxy modulation (an x,y,z lfo basically) found in Arturia’s Jupiter 8V.
Would be nice to at least consider,
Peace