There’s also a risk when heavily sedating a dog, even more so with a dog of unknown history and health status. Many vets will not be comfortable with that level of sedation in the field even if they are present. With a TNR program there’s no owner to cry and sue if the dog dies from sedation.
That’s what I was asking about ownership/age/health.
You’re best bet is time and a trap. Sorry to say but that’s going to be the least stressful and safest for all involved. If the dog is in a contained environment you can try using 6ft chain link fence panels and walking them in until he has nowhere to go but in a crate. Likely though the dog will just jump on top of the crate instead but some choose to hide instead of run.