CFR 1.401(a)(9)-6 Q&A-12 addresses the valuation of a deferred annuity prior to the commencement of periodic payments. Generally the custodian must include the actuarial value of any "additional benefits" in the FMV. A death benefit can be excluded under some circumstances, but I'm guessing that the circumstances here don't to qualify for exclusion of the death benefit. The custodian is in the best position to make that determination.
https://www.law.cornell.edu/cfr/text/26/1.401(a)(9)-6
Of course having too little cash available in one's IRAs to be able so satisfy the RMD presents a problem. One does not have the option to simply not take the required distribution without incurring the 50% excess accumulation penalty, but for now it seems that there are sufficient funds in other IRA accounts to satisfy the RMD for the IRA annuity.
Perhaps the only long-term option is to annuitize the IRA annuity (commence periodic payments). Distributions from the IRA annuity would generally then be their own RMD. Are you sure that the death benefit would be lost?
