I haven't tried it myself so you might be right, but I was thinking of the silver conductive pens from Chemtronics with a conductivity of 0.02-0.05 ohms/sq/mil.
For attachment, I'd evaluate their conductive epoxy or maybe glue down the underside of the component and then smother the lead with the silver conductive ink. But again, just hypothetical since I have a quickturn shop make cheap prototype PCBs for me and either hand solder or use a stencil, paste, and a hot air gun for my hobbyist projects.
Yes, conductive ink has too high resistance; at least the one that works on a basis of carbon; a "trace" can easily have kilo-Ohms, and the metal ink interface makes things worse.
I remember reading some "Sputnik" magazines from the 1970s where Russian scientists were searching for the holy grail of a good conductor resin. I didn't understand at the time why they found the (concept of the) thing so valuable; but now I've got an inkling...
For attachment, I'd evaluate their conductive epoxy or maybe glue down the underside of the component and then smother the lead with the silver conductive ink. But again, just hypothetical since I have a quickturn shop make cheap prototype PCBs for me and either hand solder or use a stencil, paste, and a hot air gun for my hobbyist projects.
https://www.chemtronics.com/circuitworks-conductive-pen
https://www.chemtronics.com/circuitworks-conductive-epoxy-2