I wouldn't be so worried about reducing injector life but more about running out of injection window. In the midrange, where fuel pressure is starting to ramp in properly, you don't want any more than 8-9ms. Slower engine speed means longer window to spray. At 7k, you want to be sub 7ms for healthy margin, sub 8 for safety. 9ms is the injector almost flat out and 10ms is approaching misfire territory. A strong K04 car with 130bar rail pressure will run 6s.

On the EA113, the injectors are sensitive to over-pressure. They're designed to run 110bar but stage 2/2+ setups will run up to 134-136bar. For hybrid turbos, 155-165 and even 175bar rail valves are used but it's at these levels that the filter baskets start to break up and injectors generally fail. If you're having to run more than 150bar to fuel the setup, you want to swap to a better injector.

Thanks for your input. One reason I ask, is because we had an injector failure, and I remember seeing 11/12 in the logs 6 months ago, the last time I saw the car (not my tuning). Car also had 100k miles, so multiple factors. Maybe ms was high because the inj were old/partially clogged. Have to find the log(s).