Does “testfor” send a different redstone signal depending on how many entities it found?

Note: I'm currently away from a device that can run bedrock edition so I can't test this. Please test before taking my word for it.

According to the testfor command docs:

On success, produces a success count equal to the number of targets matching player, which can be measured by a redstone comparator facing away from the command block.

If it sent the same signal strength regardless of the number of entities found, it wouldn't be possible to measure.

So yes, the signal strength does vary depending on the number of entities found.