Here's my universal launch dolly. I've used it now with the SAPAC Gripen, the GWS A4 and the FlyFly Mirage. I hope it works with the big Su-33 that I'm scratchbuilding and the Haoye F-18.
The tail wheel is free castoring and tracks well if the field is smooth and the plane is centered well. The only plane listed above that has rudder is the Gripen and it does help. Only real issue I've had with it is that it won't work in summer grass because the ride height is pretty low with those wheels and the low cross piece.
The dolly tracks much better now that the rear support is wider and holds the fuselage more securely.