Obviously it's up to you. I can see the plates but you're missing the point. That 1/4" plate is welded to 18gage sheet metal that is one layer thick. You need the cage behind that to transfer force, or if the front's hit hard enough (let's say a faster competitor breaks an axle at 1/2 track an veers into her lane) the bar will punch right thru it, plate and all. Also, having to grind any chassis member to make it look good, is a sure sign that it's not welded well or safe. Grinding of tubing welds at the tracks I go to is a fast way to fail tech. That's because last time I checked is not acceptible in the NHRA rule books. Not sure about IHRA.
Just out of curiousity... How many of Ray's cars ever crashed? Have you seen many others built like it? The reason I ask is I haven't and I've been doing this for almost 25 years now. The builders I know of use tubing fromed with a bender to bring the bar up and out from the frame, out a little more, connect and gusset the shock mount, and then hit the firewall below the cowl cap to better align with the cage. As I said, it's up to you, but the reason for safety requirements is for the one time the driver needs it. Not for the 40yrs that they haven't. You are placing a tremendous amount of trust in Ray. My concern is based on the engine numbers he's giving that I don't agree with. If you don't have the knowledge base or background to tell where he might be cutting corners that are fine in his estimation and with his life, but might not be with your car and your wife.