Please check you Coolant Temp Sensor located on top of the intake. This sensor communicates quite a bit of useful info to the ECU. I had hard starts in the morning until I replaced this little guy. Solved not just my starts but also my temp gauge in the cluster. Hope this helps....

 

I’m pretty sure the little bit of fuel that dribbles out won’t cause any serious issues.

 

Finally bothered to get everything taken apart and popped the new injectors in. Is there a way to pressurize the system without bolting everything back together? I definitely want to leak check while everything is visible and accessible. Especially the ancient fuel feed line at the bottom of the rail

 

Just an update for anyone that may stumble on this thread in the future. New injectors were 100% the issue here - number 7 plug smelled strongly of fuel. Popped them in and it starts perfectly now.

Any wagers for fuel dilution percentage on my next oil analysis?

 

Oil diluted by gasoline will undilute itself when it gets warm for a while. Deliberate oil dilution with gasoline on light aircraft engines is common (at least it was when I used to work on light aircraft in northern Canada), so you could start the engine the next day. In the morning you would simply start and run the engine for a while to evaporate the fuel.
Having said that, an oil change won’t harm your engine.