Hi everyone. as many of you know it's possible to control port injectors via oem med 9 ecu. And one company in France doing such projects but they do not sell solution.
So the question is = how do the make it?
I think that they use one single output of solenoid which controls intake manifold flaps and which one are deleted during port injector installation

Adding this feature on your Oem ecu is a very hard work...
Find a pwm output available is easy job, but reworking Ecu Sw for adding specific code for drive port injection properly is another story... definitely not a few days projets.

You're right, if we consider that the goal is to pilot this in full group, with a WMi type approach. This is what the company mentioned above does.
On the other hand, if the objective is to perfectly dose the additional contribution, in semi sequential mode, subject to the crankshaft position, it is a whole other story.
But nothing is ever impossible.

Yes, so put a switch under the pedal, with a 1€ relay and it's done....

Technically, that's about how wet shot nitrous works

You still have to have PWM control for the quantity of the fuel (well more rather crank sync set and stop pulse). But at high load any sequential control is completely irrelevant.
You could even do this with TB injection (mono-injection), but it would be hard to find an injector so big that has good atomization. WMI works great this way with two nozzles.

Of course the injected fuel has to relate to load, as well as fr_w should affect it - but it's not exactly rocket science.