That's almost it but the DSPR1 is more like a PID with control pulse output. The OP was asking about a SSVR.
The only way I'm aware of switching between a PID controlled SSR and a SSVR as it applies to a single element is to use a high current double throw switch with the element on the common. GR3, you mention wanting to avoid messing with the PID when going manual. Here are the two scenarios...
1. As mentioned above, double throw switch can select between PID and SSVR. To go to manual you throw the switch and adjust the knob. With this solution the PID cannot regulate maximum power applied and it will cost you a switch. (on the other hand, you should have a positive disconnect anyway so you could use a DPDT switch with center off to kill two birds. Google Bryant 3025.).
2. Use the inline method I mentioned. To go to manual you set PID to 220F and adjust the knob. Again, the benefit is being able to use the knob at any time even when the PID is at a realistic set point. You don't mention if you're planning to use it for BIAB or mash control of any sort so the value of setting max power in PID mode can't really be determined. Because I use a recirculating eBIAB system, it's extremely valuable. Without the need for a double throw switch, you can achieve positive disconnect with a cheaper single throw switch.