Engine mounts diagnosis?

[sailabroad]

Yanmar 3jh4E 1100 hours 8 years old with yanmar 100 & 150 mounts.

Is there any way to check if my engine mounts need to be replaced? If they have gone 'soft'?

They have not collapsed, the space on top of the rubber is more than a finger and the same on all 4.

Revving the engine in neutral almost all vibration disappears above 2200rpm. When in gear there is a lot more vibration which is why I'm concerned.

I found on the internet some yanmar mounts have lasted 15! years despite the recommended service period of 4 years.

There is more fore and aft vibration in gear than 6months ago but it is still small.

Dragging the propeller in neutral shows some vibration which I wonder if this means the prop shaft is bent?

Engine Flange alignment is within .03mm and I just replaced the propeller cutlass/sleeve bearing.

I read that the engine bracket+mounts should not move more than 3mm when revving hard from neutral to max rpm and then the same in reverse

Any input would be very much appreciated especially considering the price of OEM engine mounts