Yes it is best to first install the new injectors then start engine,
let engine warm up to normal and let idle for a good 5 minutes so PCM can relearn idle using new injectors.
Then driver the car for about 1 hour so PCM will relearn and re-cal for injectors using different engine loads.

After that the PCM tune should be done for PCM will have by then averaged out for new injectors.

Dyno tune is a waste of time for your ONLY seeing the few conditions and fuel trims used on a dyno which is nowhere near real world driving where all engine conditions, shifting, A/C, etc are used and PCM is adjusting for all of them not just the 20 seconds on a dyno with no idle, shifting lifting of gas pedal etc.

Using a PCM scanner recording while doing the different driving conditions/loads and then using that recorded data will get you a much better overall tune then a dyno will and how I haved tuned close to 200 cars