NRB for lifetime transfers

If you have CLTs and PETs seven years prior to death, does the nil rate band include the PET when deciding entry charges?

Example:

CLT 1: 100k

PET: 300k

CLT 2: 100k

CLT 1 is obviously safe as it uses up 100k from 325k of NRB.

But does PET use up the remaining 225k as part of its 300k gift, meaning CLT 2 has no remaining NRB and is entirely subject to 20% entry charges?

Or does PET not use up NRB since death has not occurred, meaning CLT 2 is still within NRB for the entry charge? It’s only at reassessment if the donor dies within seven years that PET would use up NRB and CLT 2 would be subject to IHT.