Are beam style torque wrenches accurate at the end of their range?

If it's only 5 ft. lbs., then you are probably going to over torque it with a beam-type wrench. They aren't super accurate down around 1-10 lbs.

What are you torquing? 5 ft-lbs is 60 in-lbs. That is about the twist of a wrist. Get a 0-100/150 in-lbs torque wrench if you want accuracy.

for 5 ft lbs, on a 150 ft lb scale, you're looking at a needle displacement of 1/30 of full scale. That's not much, and not easy to read precisely.

You need a quarter inch click style. https://www.harborfreight.com/14-in-drive-click-type-torque-wrench-61277.html
I don't know who would bother torquing a bolt or nut to 5 lbs.

Well, you can use your beam style torque wrench to torque roughly 5 ft-lbs. Measure the handle in inches and fasten a fish scale to the end. Calculate the amount of force you need to exert on the scale for 5 ft-lbs, or 60 in-lbs. If the handle is 15 inches long, you need 60/15 = 4 lbs of force. Put the wrench on your victim, pull on the scale until it reads 4 lbs. Next lesson: use a wrench to drive nails.

A physics student was given an assignment to explain how a barometer can be used to determine a building's height. His answers: You can take the barometer to the top of the building and throw it off, timing it's fall, then calculate the height by the fall time. Or, you can lower the barometer over the side with a rope, then measure the rope. Or, you can approach the building superintendent and say, "I will give you this fine laboratory grade barometer if you will tell me how tall the building is."

The 'beam style' are LESS accurate across the ENTIRE range than the 'click style' because they depend on YOU reading the position of the needle.