Whatever the niche topic is, when there are multiple communities that maybe be broad enough to contain your audience, there’s probably a lot of overlap in subscribers. So yes do crosspost, and do it immediately, but only cross any given post to 2 or 3 other communities. Then it won’t feel like large spam to people subscribed to all of them. I prefer to scroll by a set of 2-3 crossed duplicates, one right after another in the feed (because they were all posted at the same time) than to have one post seem to repeat with some time separation.
Whatever the niche topic is, when there are multiple communities that maybe be broad enough to contain your audience, there’s probably a lot of overlap in subscribers. So yes do crosspost, and do it immediately, but only cross any given post to 2 or 3 other communities. Then it won’t feel like large spam to people subscribed to all of them. I prefer to scroll by a set of 2-3 crossed duplicates, one right after another in the feed (because they were all posted at the same time) than to have one post seem to repeat with some time separation.