As part of the loft conversion, i have to upgrade 2x doors downstairs to fire doors. Don't want to put the strip in the door as feel it would ruin the. I have a Katsu router which would be perfect to do it but the fence supplied wont go in an further, plus it too big height-wise as will hit the architraves. Sample of what I want to achieve. these linings were machine for me at the timber merchants. Katsu router with guide. Base of router with guide. Door linings I want to route out for the strip. Will be removing the door stops. Other than making a jig is there any other way to do this. I know the router wont reach upto the corners an the bottom of the frames, so will need to finish this by hand. Router has 4 screws which secures the plastic base to the bod of router, thinking I could make something with ply using these fixing points?