Form 8962 Allocation Edge Case

My friend had a health insurance plan through the Federal Marketplace for his spouse only. The plan was only active for the month of January, at which point it was determined that the spouse was eligible for Medicaid and the couple terminated their Marketplace plan. My friend received a form 1095-A for a plan that covered only the spouse, with amounts listed only for the month of January—all other amounts were zero.

During the year, after January but before July, my friend moved out of the residence due to being a victim of domestic abuse. He will file Married Filing Separately for the same reason. No change was reported to the Marketplace because the policy had already been terminated. The policy was not shared between people in different tax families because it only included one person, who is now in the other tax family. However, he is the recipient.

The SLCSP is likely incorrect due to the changed tax family size. My friend also moved to a different ZIP code, but there it is easy to identify the "affected months" as being later in the year and not having a policy associated with them. However, the tax family change seems to affect the SLCSP for the entire year.

He would like to allocate some of the credit to the spouse.  The instructions very clearly lay out situations in which the allocation must occur, but his situation does not fall under required allocation due to the plan not covering at least one person from each tax family. However, nothing in the instructions seems to prohibit electing to allocate policy amounts. The circumstances seem to align in spirit with Allocation Situation 2 and the domestic abuse exception, but since Situation 2 requires at least two people to be covered by the plan, a strict reading of the instructions seems to throw him into the "other" Allocation Situation 4. However, the SLCSP is likely incorrect, which again seems like Situation 2. The calculation for Allocation Situation 4 in the case where the parties cannot agree is interesting because it comes out to 1/1 (100%) for my friend and 0/0 (undefined; catastrophic error) for the spouse. So they had better come to an agreement, for the sake of humanity (I jest). Or, since the core issue is the splitting of a tax family into MFS families, he should just go to Allocation Situation 2. Maybe the solution is to allocate premium and APTC 50/50 and then lookup the correct SLCSP to use, which also seems to align with the general notion that the SLCSP on Form 1095-A can be incorrect when changes are not reported and that the correct SLCSP should always be used. It also seems to align particularly well with the instructions for the domestic abuse exception in situation 2, which are precisely that).

However, my friend is unable to use the online tool at HealthCare.gov/Tax-Tool/ to calculate the correct SLCSP because, right out of the gate, the answer to "How many people in your household meet all of the above requirements" about being in his tax household and also being enrolled in the plan is in fact zero, and the tool requires a response of 1 or higher! So is SLCSP just... not defined at all?

There is also this language in the instructions, which seems to be trying to address an edge case: 

"Individual you enrolled who is not included in a tax family.

"If you indicated to the Marketplace at enrollment that you would claim an individual in your tax family for the year of coverage but the individual is not included in any tax family for the year of coverage, you must report any APTC paid for that individual's coverage. Follow the rules under Column (f), earlier, to report this APTC."

But that doesn't seem like it should apply, because the enrolled spouse is included in a tax family! The spouse will file a tax return (MFS). If they can agree on an allocation, the spouse can be provided a copy of the 1095-A and can reconcile the allocated amount, whatever it is. Such an agreement seems possible, because the spouse has an unused child tax credit that could absorb the repayment entirely. Also, in this case, it is the enrolled spouse, not the individual who enrolled the spouse in the plan, who would be able to easily find the correct SLCSP using the online tool. The correct SLCSP for my friend's tax family seems possibly not even defined for him anymore. Nobody in his tax family was ever enrolled in the policy. In fact, the policy seems like it should belong fully to the spouse's tax family. And it would be mutually beneficial if that were the case!

There seems to be a gap in the instructions when nobody in the recipient's tax family is enrolled in the policy. Can my friend and his spouse agree on an allocation in this scenario even though one is not required? Any thoughts on how to proceed would be appreciated.