Blackfoot griz ! processor questions!

[bigblue12v]

Just joined after searches led me here to some of the best processor building info I've seen. I realize there's a ton of threads on processor builds. I've skimmed through them and everyone is doing their own a little different than the next guy. I'll try not to ask questions that have already been addressed but please pardon me if I do.
I have never seen a processor in person. I'm scheming a build which I may be fortunate enough to start this winter. Last winter I built a splitter which has been working great and about as planned. Great learning experience. Now I find myself hauling in wood faster than I can keep up with. I don't NEED a processor. I want to build one. I need a good project I haven't done before and I'm always building things. I won't post my resume but I'm not new to fab work and engineering things but I'm still learning a lot about hydraulics. Since I just joined today it won't let me send a private message. So I'm calling out Blackfoot griz here because his build is close to what I'm planning.  I also think I'm going to closely model mine to the Dyna SC14.

Here's what I have I'm thinking of starting with:
Jacobsen front mower as a donor:
Kubota D950 3 cylinder diesel 21.5 HP 40 ft/lb torque. Has a 13 GPM single stage pump mated to the hydraulic driven deck motor which I think this circuit should power a saw provided I get the gearing right which may require a jackshaft belt driven by the pump. Convenient as it's already configured for a pulley. Would allow easier tuning of chain speed and torque switching pulleys and belts as needed. Also would allow for easier fitment of a sprocket since most people have difficulty finding one to fit their motor.
I'm planning a 4 or 4.5" cylinder custom made with 3" piston and 3/4" ports, using a dump valve. Powered by a 16 GPM single stage or 28 GPM dual stage pump. Have not decided yet. I think I can turn a 16 single OK depending on pressures. I made a log splitter attachment that's currently running on the 13 single pump and at half throttle it doesn't bog the engine much after stalling the cylinder. Haven't checked pressure but tech manual specifies it should be adjusted to 2600 psi for proper mower operation. It mows perfectly fine so I assume we are in that ballpark. I'm questioning whether a 4" cylinder is enough to power a 4 or 6 way wedge through tough knotty wood. This is where I am thinking perhaps a 2 stage pump would allow me to crank the pressure up without suffering power loss as I might experience with a 16 GPM single stage. The Dyna sc14 comes standard with a 30 HP Kohler which is about the same torque as my diesel and they're using a 4" cylinder with reported 7 second cycle times. Of my cycle time is fast like that, I'm not worried about cutting the next piece while splitter is cycling so I don't mind splitter pump using 75% of engine power if need be. But this also depends how fast the saw can cut. I want to handle up to 18 maybe 20" wood. Maple oak walnut hickory etc. Expect knots etc. I question if a 4" cylinder can handle this with a multi way wedge. I realize a lot of efficiency depends on the wedge design and plan on maximizing this.
I don't want to spend most of the splitting stroke on high pressure low flow mode though, 7 GPM is too slow. I know Griz stated using a 2 stage 28 GPM but didn't list his cylinder size and I only saw one video showing it splitting one or two pieces briefly. Most YouTube hits on a search for 28 GPM splitter involve bigger cylinders and or smaller restrictive hoses so it's hard to find relevant material.

I plan on using a third , lower flow single stage pump for accessories: adjustable wedge, log lift table (no way to load a live conveyor so a lifting table for now), log feed conveyor, etc. I don't really envision needing to demand power from more than one pump at a time typically. Maybe moving a log into position while the splitter is on return stroke. I want speed but there's a lot of ways to get there, different cycling operations and sequences, cycle speeds etc. I think I want to keep fastest saw and splitter speeds and not worry about overlapping those two cycles. I think consistency is a strong key to efficiency. I'm also very interested in that one touch valve setup Griz is using. So I hope I've given enough info without overwhelming and I hope Griz replies and can help me out here. I would LOVE to see a lot more video footage of your machine!!!! Lots of processors on YouTube but most give few details that help me research.

Thank you in advance for any helpful information!!!!!
Eric ( Seymour Indiana area)