Adding lower bar for trike mount?

I am very interested in the SP140 V2 frame, but would need to mount it to a Colibri trike. I have seen a couple of videos of other mounting it by drilling holes in the upper frame bars for thumb screws, but the Colibri has existing U shaped mounting connectors where the P2F frame’s lower cross bar goes through. The SP140 frame does not have this front lower bar, but if it did, it would be a perfect match for the Colibri trike. I am not a welder, but how hard would it be to add a crossbar to the lower part of the frame? Preferably via some type of removeable connector, but I would be open to having it welded as well.

I have include a screen grab from another SP140/Colibri builder that shows better what I am talking about.