@User: I have run voltages on the 1.8V devices up to nearly 3V, but I wouldn't recommend doing a design that regularly stresses any gate with that voltage. The current open_pdks has "basic" support for ReRAM in that you can draw such devices and they will extract, write to GDS, and be checked for DRC. I have not gone through the process specs to work out all the parasitic capacitance changes that correspond to the larger distance between metal1 and metal2. Once I get around to that, I'm going to split the process between two variants "sky130A" (normal) and "sky130B" (with ReRAM). For now, you'll just use the usual sky130A and be aware that the parasitics are incorrect.