Hey @Dxstat I could be mistaken, but staying in London would not cause the IL to be delayed, regardless of whether you react. If you want to return to your native country, they advised you to use the public inquiry form.
A friend of mine who received his IL last month end (he transferred his case from his home country to another country) received this on Friday, along with instructions on how to verify residency when he arrives for his interview. I've attached what they sent to him here. I hope it helps.