It's probably not actually a hydraulic lock unless you have flooded the engine but just coming up on the high compression point. A stronger battery/starter may help there.

This is a typical problem with plastic spinners and there is not a whole lot you can do. Make sure the cone fits well and has approx the same taper as the spinner and the surface has not hardened.

Some people allow the starter to come up to speed and then jam it onto the spinner. This will usually work but can be dangerous if alignment is off. Not a recommended proceedure. Metal spinners work well but are more expensive of course.

Oh yes, keep the spinner clean and dry. Keep fuel off it. Remember there is oil in the fuel.

On the bright side, spinners (plastic) are cheap.