@jupiter - thank you for documenting your experience. It has helped me in my project. I will make an observation after having tried your advice... Max Shakiness 10, Max Accuracy 15 with Zoom 0% and Smoothing between 5-40. It appears the stabilization tends to work well for the first 35s of a 14m video clip 1280x720 H.264 30fps. The analyze function creates a .stab file approximately 225MB. After exporting the first 35 seconds without changing any video settings (except Interpolation from Good to Best and playing with the Parallel Processing checkbox), the stabilization is no longer evident in my video and the shakes resumes to the point of the original file. I've tried lossy and lossless exports. To combat this problem, I used Avidemux to segment the video into 30 second clips, then apply the stabilization to each in Shotcut, analyze and export again. This appears to be a workaround but is very time consuming.
Many thanks to the incredibly talented development team and directors and for those members of the community that share their time, knowledge and expertise with the world!