Mazzilli (ZVS) oscillator improvement (start-help)

I used a Mazzilli ZVS oscillator for a project involving wireless power transfer.
I used an adapter as a power supply to power the Mazzilli oscillator, but I noticed that the oscillator didn't always start.
When the oscillator does not start, one of the FET's latches into conduction and remains conducting while the other FET stays open.
After a while, the result is the distinctive smell that every electronics engineer immediately recognizes, knowing that something got hotter than planned.
Below is the standard circuit of the Mazzilli ZVS oscillator :

I discovered that the problem was due to the slow and irregular startup of the power supply.
The power supply voltage did not rise fast enough and had some bumps down the road.
So the choice was either to find a power supply that had a faster startup time or to find a solution that would allow slow starting power supplies.
The last choice is of course the best one, but not the easiest.
The circuit below shows how i solved the issue using a time delay. The time delay ensures that the 100E MOSFET gate resistors are connected
about 250ms later to the power supply than both the drains of the MOSFETs.
The time delay circuit is built using transistors. Q2 and Q3 form a differential amplifier. At power on, R1 will start charging C6. The voltage over C6 rises until the threshold voltage, that is set by R3 and R7, is reached. At that moment, Q2 will start conducting and pulls the base of Q1 low. This means that Q1 will start conducting and thereby connecting the 100E MOSFET gate resistors to the power supply. Both MOSFETs will turn on, but only one MOSFET can win the race. The winner will start conducting and will block the other MOSFET via the Schottky diode.

Click here to download the LTSpice simulation of the time delay circuit