You could "production line", but it would be a right pain to organise and keep running sweetly. The jobs would be : taking off the manifolds, drilling and tapping, fitting the nozzles and refitting the manifold, fitting the injectors and plumbing, ECU and general wiring, fitting vaporisers, fitting tank, doing tank plumbing and wiring, setting up and tuning. Trouble is there is a lot at the front end and people would get in the way.
The idea of easy stages without disabling the car seems most sensible to me. I lent Tunnie my spare 2.2 inlet manifold, so he can get it drilled, tapped and the nozzles fitted first without disabling the car. Fitting the manifold, injectors and vaporiser and front plumbing is an easy day job, and the car remains usable. Wiring in the ECU and checking you have communication, you can poss check the vap water flow is getting up to temp, another easy day. Fitting the tank and plumbing, well a weekend taking it easy, but that's it already for final testing.
Remember we are getting to the cold part, and you will be physically limited as to how much you can do, unless you have a heated garage. I feel its better to take it easy, not rush and hence less chance of mistakes. Remember a broken tap in a manifold can take a long time to get out. (hence having a spare manifold makes sense)
Ken