flame sensors with BCS-462?

I am just venturing into the beginning stages of planning the build of my BCS controlled, automated home brewery. I am leaning toward using solenoid valves on my gas lines (high pressure LP) combined with direct ignition from a hot surface ignitor, both controlled by the BCS. I would like to add a safety in the form of a flame sensor, so in the event that the ignitor fails the main gas valve would be cut off.

My question is could I integrate a typical home furnace flame sensor into the BCS to work as part of the burner ignition process with the hot surface ignitor and gas solenoid valve, or would I need an additional control/interface device? I have zero experience working with these types of things, and everything I have learned so far has come from reading posts from those who have built systems like this.

I would avoid the hot surface ignition route because of the fragile nature of the carbide/nitride ignitors. Other systems have appeared on HBT that do not use the correct ignition hardware and are taking considerable chances if hot surface ignitor is damaged and does not heat before timed interval has passed and gas valve is opened.
The Honeywell S8610 spark ignition and pilot burner route is the safest and easiest to build with because it will withstand spills and mechanical impact within reason and still continue to function. The BCS is not designed for flame safety applications, but can be used to switch power to the ignition modules meant for that purpose. You apply 24VAC to ignition module and it in turn directs power to the pilot and main gas solenoid valves connected to it, and it monitors the presence of a flame at the pilot for safety.

Thank you for the help. I was avoiding the low pressure valves because I was told that the low pressure propane would not perform as well as high pressure, is there any truth to this? When installing the Honeywell valves, would you position a needle valve before or after the valve to control the flame, or just use the adjustment on the furnace valve itself?

There are a growing number of systems built with the low pressure honeywell standing pilot valves and the BG-14 burners that give plenty of heat for traditional 10-15 gallon systems. This is the lowest first cost method that is the easiest to build, but requires the pilots to be lit at start of each brew session. The hands off method with spark ignition is about twice the cost but roughly the same effort to assemble.
For flow control you always place the flame level control valve after the automatic valve, and then adjust the maximum flame with the automatic valve pressure adjustment and flow control valve wide open. You will find that a ball valve will work for the flame level control on the low pressure systems where the flow rate is higher and the gas density is much lower than the 10 PSI + systems.