Polesaws are just saws on poles. They can be manual saws or powered (electric chainsaws, gas, 2 stroke). Have not seen a diesel, saw a rare hydraulic.
Manual work real well with a sharp blade and a strong arm. They are relatively light weight compared to a powered saw but you provide the power.
I've a lot of hardwood trees that need trimming down in Mississippi. Mostly gum. I was using a 17' telescoping fiberglass polesaw. Worked well but I don't think I ever got through a 4" diameter branch in 7 pulls, especially not after the first couple.
So I bought an Echo PPT 280 w/ 4' attachment, this let's me go out 17 feet. Basically a 30cc chainsaw on a stick. Like a Stihl MS 170.
Here's my son using it at 12'
Here's most of it w/ attachment
and here's the first limb I cut at full 17' extension
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That being written I'm probably going to be getting a Lynxx 40V pole saw, just to add to my toolset. I can envision using it when I'm up in trees or on a ladder.
To the OP - If this is going to be occasional use determine if you will want other tools that will use the same battery.
Check for the possibilities of extensions.
Look for youtube videos of it's use.
Find an assembled one and hold it out at full extension for 5 minutes to see if you can handle it. They get heavy quick.