Aside from clipping to a device terminal and randomly looking at the signal, it makes far more sense to obtain the circuit of the device and either connect to the required points or else remove some f the solder resist and solder to the traces on the PCB.
What signals are you hoping to tap into??

 

I think I found the thing I was talking about.

https://www.geeky-gadgets.com/pcbgrip-electronics-assembly-system-video-10-01-2014/

Sadly it seems there was only this one product and it's not made anymore.

I thought this was "a thing" I just didn't know the name for. "probe positioner" and "probe holder" are the closest things so far.

 

Aside from clipping to a device terminal and randomly looking at the signal, it makes far more sense to obtain the circuit of the device and connect to the required points

It's a chinese amazon special electronic device, no schematic if that's what you mean

or else remove some of the solder resist and solder to the traces on the PCB.

Good call, how's the best way to remove the resist?

What signals are you hoping to tap into??

See below

I would like to get a signal of exactly what's on the LCD, because the rangefinder has other features like compass, level, et. al, and calculates the hypoteneuse if you're aiming up hill or down hill. [...] It would be super cool if there is a diagnostic bus on it somewhere that is just puking out strings of all the info I want but I doubt it. I want to rule it out though.

 

I read what I wanted to read there.
You didn't say anything about soldering wires on.
So how do you probe the blobs? With the clips you recommended? Or Just by hand?
What about probing 4 pins at once?

It's using the clips, no extra wires. Some PCB layouts are easier to probe than others but I only try pin one at a time as usually there are alternative sites on the board for pin signals.

If I need to use wire then it's usually this stuff: https://www.farnell.com/datasheets/3179335.pdf

https://forum.allaboutcircuits.com/threads/blinky-prop-for-comic-con.127266/post-1038151

 

It's using the clips, no extra wires. Some PCB layouts are easier to probe than others but I only try pin one at a time as usually there are alternative sites on the board for pin signals.

If I need to use wire then it's usually this stuff: https://www.farnell.com/datasheets/3179335.pdf

https://forum.allaboutcircuits.com/threads/blinky-prop-for-comic-con.127266/post-1038151

Do you use the wiring pencil? I haven't seen one of those in use in a long time.

 

Do you use the wiring pencil? I haven't seen one of those in use in a long time.

I've got one but don't usually use it.
https://www.farnell.com/datasheets/3179339.pdf
https://www.farnell.com/datasheets/2575106.pdf
https://www.newark.com/roadrunner/rrp-123/wiring-pencil/dp/05WX1121

 

I've got one but don't usually use it.
https://www.farnell.com/datasheets/3179339.pdf
https://www.farnell.com/datasheets/2575106.pdf
https://www.newark.com/roadrunner/rrp-123/wiring-pencil/dp/05WX1121

It was a pretty cool prototyping system at one time. It's one of those things that some people know about and everyone else never heard of it—it tends to break across age lines.

 

Solder mask usually scrapes off without too much effort. Making just a narrow scrape you may be able to get solder on just a very narrow strip to solder on a thin wire, say #32 or #34.
There is probably a driver IC for the LCD, and the lines to that should be easier to trace. And if it is a device with a part number that can be looked up then you can discover the connections of the data signals.

 

There is probably a driver IC for the LCD, and the lines to that should be easier to trace. And if it is a device with a part number that can be looked up then you can discover the connections of the data signals.

The chip shown is the LCD driver and the three pins of interest are a serial data, clock and a read/write pin.

 

I think I've decided on this

plus this.

When I found the PCBite stuff on SparkFun with no reviews I was concerned about the flexy arms not being sturdy enough, but I found it on Amazon and it has decent reviews so...

Also PCBite makes this scope probe version. I'm not getting it, but figured some folks here might find it useful.