I would also add a 1k or so resistor across base emitter of Q2, as the turn on might couple enough charge to turn on the pass element transiently, and any leakage in the transistor will cause voltage to rise, especially as the pass element and driver get hot with high current operation. Additionally change R16 to a 470R resistor, 1k is a little high to handle leakage in a 2N3055 as it gets hot, and a better transistor to use there is a 2N3773 or 2N3774, which has a lot better SOA area and much improved thermal characteristics over the old venerable 2N3055.
Replace R15 with a pair of resistors in series, probably 1k in series with 2k7, with the junction of the 2 resistors having a capacitor of 10-47uF 35v connected from the junction to your common ground rail. This will mean the voltage to turn on the pass elements is slow to rise on power on, and thus there is time for the control loops to stabilise and pull the output voltage down before there is enough current flow in the control loop to turn on the pass transistor. The capacitor will not have any effect on the loop itself in normal operation, as Q5 is being current driven and thus has a near constant 1V2 on the control line.