Hey there! You can get kind of modular effect modulation in renoise - think out of the box, instead of the nodes you have the tracks and meta devices. Some moves really need some trickery to work, and then things can get tedious to set up unless you can just use a doofer. But if it doesn’t disturb you, you can go for it.
You should try using the modulation in Track DSP FX for anything not polyphonic, and modulate the synths via macros etc - it has more freedom of routing etc. For example your task of making an LFO to reset another one each cycle, could be coded with formula devices somehow. Then you only need to start the LFO at being of track with a pattern command. But you have to use workarounds, like using two LFOS for the slow rise/fall and then the retrigger of the stepper.
BTW. you might like my Track DSP FX Stepper setup for this, it has some thought put into it to turn a formula device and a LFO into a proper stepper! Look here: DSP FX Chain Stepper