Change nationality outside UK while holding a Tier 5 BRP

Hi guys,

I am intending to come to the UK with a tier 5 visa which is already approved. I will be collecting my BRP soon after I enter.

However around the same time my visa got approved, my citizenship application with Singapore also got approved. If I need to take up the citizenship I need to come out of UK and renounce my current passport

I am wondering whether I can re-enter the UK with the BRP but with a different nationality and passport?

Once inside UK I am aware that it is possible to change the nationality on the BRP by transfer of conditions and Singapore passport usually allows visa free entry into UK. So I am wondering whether I will be allowed entry to the UK with the new passport

Regards,