My Berlina has a similar pause on tip in, and also it isn't as noticeable on warmup. I have a wideband so I can see it go a bit leaner then come back. Which makes sense to me, as you're opening the throttle I assumed you're getting more air faster than the fuel can catch up.
Other than that mine runs great, starts in cold weather, runs pretty close to 14:1 on the freeway, gets good mileage. One of these days I'll get the factory bellcrank tool and go back through and double check everything again.
I'm happy to post a video of the wideband if I get a chance.
Ian Lomax - Current: 1973 Berlina, 1987 Milano Platinum "racecar"
Past: 71, 74 Spiders, 2x 74 Berlina, 74 GTV, 76 Alfetta GT, 88 Milano 3.0, 164LS