Symphony keys

When I  took ownership of my 1997 Peugeot Boxer Symphony 4 years ago, I was given a burgundy master key, two black ignition/door keys and an obvious copy. No code card. It was only later that I learned the significance of the original keys but thought nothing of it. A couple of weeks ago I lost one of the black keys which has a transponder chip. I have found a place that will cut me another for £80 but would need the van for an hour. I'm pondering this option. Meanwhile I tried the non-transponder key expecting the "code" light to illuminate and for something like the fuel pump to be deactivated. But no, the engine starts and the van drives albeit with the "code" light on.

I understand that it is possible to deactivate the factory immobiliser so wonder if a previous owner has done this. Could anyone in the know tell me what the consequences are of starting and driving without a transponder key or what should/should not happen. Obviously there would be little point in spending 80 quid on a new key if the immobiliser has been deactivated.

I have a 1999 Peugeot Boxer Symphony. Had an extra key cut last year - had no issues starting the van with it.
Original key, which I use (OH has other key but does not drive it), does trigger the code light on dash - thought that was normal.
Now you have me thinking.