Yup, a few times. I've had to create tables that needed to start the identity at a specific value, for example if we are moving to a new system and not importing old data yet we want to pick-up where the old ID's left off, changing the seed is critical.

As for increment, I think the only time I've had to do that is when I'm building a table of ordered items where Date doesn't work as a good Order identifier and I want to leave room to add items in between. If you ever did any old-school BASIC programming with line numbers, using 10, 20, 30 etc was critical as there was always something that needed to be added. Same thing here.

So yup, on my end I've had to change the Seed and Increment a fair number of times 🙂