First you need to know script structure. Screenplays are blueprints. Secondly, you should always meet your producer's deadlines, provided they're reasonable and you've agreed upon them in advance. If you're paid to deliver a draft in 60 days, have it ready in 55. Then if you need to make changes, you can deliver the revised draft on time.
Producers love that.
You've written for both TV and film. TV is more rigid. So I can't say I have a definite preference for one or the other. You must have a common vision. A good partner will think of angles that may not occur to you.