pick-and-place thru-hole parts?

If there's a spot for the sucker to lift the relay I don't see why not.

If the pick and place can do a 0.4mm BGA there no reason it can't put

If there's an issue with the feed tray having the relays crooked, you might need to use the camera or nudge them a bit before picking them up.

Usually they drill a stack of panels in one operation, with dummy sheets of some sort of melamine faced mdf or something on top and on the bottom of the stack. If the holes are tapered, they will have to do one panel at a time. That will cost more. As would special tapered drills that they would need.

Two types of through-hole pick & place machine visible in this art film from circa 1980:

Did they send them all to China?

(I believe the cars under construction in the second half of the clip are final round of 2nd generation Chevy Camaro)

If the holes are countersunk and the relays are large enough you could prolly program a small industrial robot to do it, just keep it fed with a tray of relays like ice cubes.

This one is 15k which is maybe competitive with used general-purpose through-hole pick n place machines, but there are probably cheaper options:

Lot smaller than a pick-n-place machine, too

Here's another delicate lil guy:

We have a new Yamaha p+p, super precise. Just thought I'd ask for opinions.

as long as the holes aren't super tight and the pins aren't too long and floppy, I don' see why not through hole used to be automated too

can't get the relay in SMD?

The available, multi-sourced ones are the 10x20 mm 1formC with pins.

I actually want about 25 formB and 75 formA, but 1formc would do for all the 100 relays on the board.

This will be a cable tester, a box one can insert in a cable to simulate opens and shorts and snoop signals.