Digital differential pressure meter for sync?

I would think that they would work fine.
If there is an issue with pulsations, using long hoses and inserting a restriction in the hoses at the end farthest from the meter would act as a very effective averaging filter.

As Bill said "I would think that they would work fine." 

No offence intended but what I can"t understand is the urge to pay much more money than you need, for a complex devise, when a cheap simple one will do the job very nicely.

I have a cheap ( I think under $20 when I purchased it 10 or so years ago) motorcycle, twin carb /twin vacuum gauge (Borden tube) set (just like the one below). It probably wouldn't suit a professional workshop, doing many carburettor balances but for the home mechanic doing a balance check every 100 hrs its near perfect.

https://www.thirdgear.com.au/2-gauge-carburetor-synchronizer-tuner-tool/

Purchase a good length of compatible vacuum hose and you can have the gauge set in the cockpit for pilot analysis, while the "first officer" does the adjustments in the blast of the prop.?

PS you can still find them for around the $20 mark.

Something this simple works as well as anything and it makes diagnostics far easier and quicker than the electronic models and it's far cheaper. The brass valves are for dampening the pulsations which can make the needle nice and solid. Using something like this usually takes me 10-15 minutes to do a carb sync.

Don't use the plastic hose shown in the picture. Use some good vacuum hose.

I have been accused of looking for excuses to buy tools :-)  I certainly don't doubt a pair of mechanical vacuum gauges will work.  Speaking of overpriced tools, I already have a CarbMate, which seems to work fine. 

This was just a curiosity since I was looking for a manometer for an HVAC experiment, and came across these dual meters I had never seen before.  You can get them for under $40 if you don't mind the generic branding.  I figured someone else had probably tried it.  

Thanks,

Rusty 

You could build one with gauges like in the previous post for about $60 - $70. The good thing about gauges vs electronic devises is you can diagnose and see things in seconds that you can't see with electronic devices.