I run Screenwriting Tribe workshop in Santa Monica, which I stared in 2016.
I am also the author of the book "Screenwriting Tribe: Workshop Handbook for Writing and Polishing Film and TV Spec Scripts."
Screenwriting Tribe consists of several hundred writers and some actors helping writers to polish their screenplays. We focus on feature film, short film, and episodics, but we don't workshop multi-cam sitcom scripts. We meet on Sunday evenings in Santa Monica.
Up to 15 members may RSVP to attend the Sunday evening workshop. 4 of the 15 writers bring 12 pages of their scripts. The pages are read aloud as we sit at tables. We give both verbal and written feedback.
It is a good way to workshop and polish a script 12 pages at a time, before showing a script to anyone in the industry, or before submitting to contests and fellowship programs.
It takes about 4 to 8 weeks to workshop a one-hour TV pilot, and about 2 to 4 months to workshop a full feature script.
If a writer also takes that time to study a variety of screenwriting books, read many articles about screenwriting, watch films that have won screenplay awards, study scripts that have won awards, and takes other steps to learn about the craft, they will absolutely improve their skill, and their script.
I also have been paid to overhaul scripts before production. It is best to overhaul those scripts, and fix potential problems before going into production. It can save many headaches and expenses, and help with everything from casting, budgeting, scheduling, and editing.