I spent an afternoon at LTE recumbent bike shop. The owner Boudewijn, from the Tripod and Tracer trikes, suggested I did less caster on the Tribolt. The tilting effect will be less as a result.
Maybe he is right. Maybe not. Point is he always links the front brakes on his trikes. Then you don't need centerpoint steering.
When I built the first copy of the Raptor I had no steering axis inclination. The handling was perfect. With 14 degrees caster. After I added my design steering the brake-steer was as god as gone, or at least very manageable. But it didn't improve anything else.
So I will do some experiments with less caster and less kingpin angle and compensate with the wheel axle further behind the kingpin.
The last word is not spoken yet about the steering. It's complicated. My L-profile setup works fine. But perhaps it can be improved by other angles, more or less Ackermann compensation and axle placement.
If you do link the front brakes, please consider the simple straight Raptor method with no steering axis inclination whatsoever. Death easy construction. I found 14 degrees working great. Less then 10 degrees and you may encounter problems with the bottom bracket height and your heels touching the road. Check before you drill.