Ideas to shorten stroke on new splitter?

I recently bought this Ramsplitter. I cut my wood to 16" to 18" but the stroke on this splitter is around 26". I'd like to use some kind of temporary fixture to get the stroke down to 20". I have very solid 6x6" block of wood I have been using but it isn't attached to the pusher plate so I have to manually reset it every time.

Ideas I've thought about:

I can slip a piece of heavy wall PVC over the pushrod such that it stops the pusher at 20" on the return stroke. I did this with my smaller electric splitter but did not know if it was a good idea with this splitter. Will the control valve still reset after the pusher retracts?

I can somehow affix the 6x6" wood block to the pusher although worried an angled piece of wood could cause this to violently kick out under heavy pressure.

I could weld up some type of slip-on extension that slips over or attaches to the existing pusher. See pic. I'd be interested in seeing pics of other similar slip-on extensions if you know of a good design.

Thanks!

Bugman/Butcher - so there is no mechanical issue with not allowing the ram to fully retract? Any idea how much force is used on the return stroke?

Thanks guys. I went low-tech for now and and reused a short section of SCH80 pipe. The inner dia was close enough and no issues with galling expected. I put a backplate of white HDPE to spread the load across the front of the ram. I can swap it out in 60 seconds should I ever need to split something over 20"