Once you get a lender to pull your credit you will have 15 days to shop around without the other hard inquires affecting you. I would say, if you can, have a lender do a soft pull to make sure your ducks are in a row prior to having your credit pulled. Our lender can do that and then he tells us what we can pay down or pay off in order to boost our credit to get better pricing

Do NOT always go with the cheaper rate. This is a big financial decision and you want the deal to be smooth and you want to know that the deal is going to close accordingly. There are nightmare stories about Rocket Mortgage. Find a lender who is referred to you by people you know or people who invest. Find a couple of options. Then talk to them and find out which one is the most transparent, reliable, communicative, experienced and has a competitive rate. Sellers often deny rocket mortgage offers because they are known to fumble last minute:

https://www.reddit.com/r/realtors/comments/10l5eo8/sellers_distrust_rocket_mortgage/