I haven’t found a preview button an option in the forum platform we are using, though I will look into that. I spend a lot of time editing my replies before AND after I post. In the old forums, I often found it easier to compose my posts in a Word doc, then cut-and-paste to the forum and add formatting. (I tended to write incredibly lengthy messages, and often lost everything I was writing when I’d “time out”).
The other change is the CAPTCHA we added (unfortunately made necessary when a sleeper bot that joined months before starting spamming threads with porn links . . . )