Over time I've gravitated to the extreme KISS solution. I don't have any special centering mechanism and I don't hold the tiller while setting or doucing.

Without a kite my rounds up gently. With a kite it want to fall off gently.

I make use of that.

After the top mark I steer the boat downwind and throw the tiller extension over the back. I reach forward hoisting the spi. The boat will round up gently but when the spi is halve hoisted the pressure on the spi (even when just flapping about) stabilizes the boat on the course of the moment. I then grap the sheet and move back and out, sometimes I grap the tiller extension but in reasonable conditions I leave it in the water and steer by the little tiller arms on the stocks.

Doucing is very similar. I steer downwind .... when doucing the boat starts rounding up slowly and pretty much when I'm finished doucing and adjusting the settings I need to move out as the boat is approach a beam reaching course.

Pretty much I'm confident that I can hoist and douce the kite in a handfull seconds; at least under 10 seconds. If I do encounter a mishap I leave the spi as it is and reach back to the crossbar to adjust the course and then continue with the spi hoist/douce. As good as always I have the head in the snuffer and so dropping what I was doing is never that much of a problem. My snuffer and retrieval setup work very well and even if the spi is in the water I can get it in relative easily.

So pretty much my approach is "fast hoists/douces and not make mistakes". This is proving to work really well for me.

I do have rudder joints on my crossbar tiller connections maybe that is helping. I think it does.

Wouter