Claim Tax Relief Now or Later? (SIPP)

I’ve just contributed about £7k into my SIPP to keep myself out of the higher tax band this year.

I’m now doing my self-assessment and wondering—do most people claim the extra tax relief straight away through their return (and get the adjustment sooner), or just leave it and effectively get it back later as a lump sum?

Curious what others typically do and if there’s any downside either way.