It can work with the right rear derailleur.
I have those MicroShift R7 shifters. No problems. They're plasticity inside but has been reliable. Metal shift and brake levers. Everything is smooth and crisp.
However they extended the reach too much for comfort so I had to switch to a shorter stem or compact drop bars. The FSA Omega compact drops are great values. At the moment I'm using a 110mm stem with the FSA bar, but anything down to 90mm was comfortable without being too upright or twitchy.
I've mostly used a Shimano 600 Tricolor (Ultegra) 8-speed rear derailleur with the MicroShift brifters on a couple of bikes. No problems with 7-speed freewheels or cassette wheels.
Highly recommend SunRace chromed 7-speed freewheels and cassettes. The teeth and spacing are compatible with both my Suntour Acushift and Shimano STI setups. Better than the low priced Shimano 7 speed freewheels and cassettes that are still available.