In Save AS you can change the line thickness from By Block to 0, but the arrowhead still dont look nice, to thick, look like flys...t
If you print to a Virtual pdf writer like TurboPDF or something else, CutePDF i used earlier, it's free, then they will look nice and you dont need to change anything.
Attached show print to TurboPDF, drawing just opened, nothing more done.
If you want to change them, use ctrl + T, click inside the menu and press D for Dimensionm scroll Down to Linear and Select that one , then OK button and you Select all of them in one go, have to repeat if you have different, like Angular or something
V20, V21, 2015/ 16/ 17/ 18/ 19 Pro. Platinum
Deluxe 2015/ 16/ 19
Windows 10 Home Premium 64 bit, 32 GB
NVIDIA Geforce GTX 780m, 1 GB