I think Brighton is a reasonable step up for him. Established PL club with a good structure. I am sure they’ll back him with some smart recruitment this summer too. 2-3 year at Brighton, and he does well, he will cement his reputation and will get a shot at a top job. He’s so young. Might even be United.
If he goes to Chelsea, the odds are better than not, that he gets fired within 12 months, and then I think the road back is harder. Though not overwhelming. If he stays at Ipswich and gets immediately relegated, and worse, they concede a ton, the perception of him will change considerably I think. If he stays with Ipswich, he really needs to either stay up, or put up a really good fight and in several metrics perform way above expectations - even if not in points.
Chelsea have had 4 managers in 2 years and are clearly all over the shop. I wouldn’t go there if I was him. Not at all. Although if he does, and he succeeds, his career will take off in a massive way. I guess it’s all about weighing the risk vs reward.