I AM NOT QUALIFIED TO GIVE ADVICE BUT...

Working in the business, I have never been told the a seperation affects anything. The only thing I normally come across is that if & when the policy matures, the company may send a cheque out in joint names. It may be worth checking with the provider. With you both still being married, the ex would still be classed as the next of kin. Also as far as I'm aware, once a policy has started, the life assured names can't be altered however, you may be able to asign it to either proposers/policyholders.