The Injured Spouse is supposed to work. However, this is not the first time I have heard of this happening. You have to weigh heavily the two options and decide which works the best for you. The only way to know for sure is to make two MFS returns.
MFJ vs MFS
https://ttlc.intuit.com/questions/1894449-married-filing-jointly-vs-married-filing-separately
If you choose married filing separately as your filing
status, the following special rules apply. Because of these special rules, you
will usually pay more tax on a separate return than if you used another filing
status that you qualify for.
1. Your tax rate generally will be higher than it
would be on a joint return.
2. Your exemption amount for figuring the alternative
minimum tax will be half that allowed to a joint return filer.
3. You cannot take the credit for child and dependent
care expenses in most cases, and the amount that you can exclude from income
under an employer's dependent care assistance program is limited to $2,500
(instead of $5,000 if you filed a joint return). For more information about
these expenses, the credit, and the exclusion see Pub 17, Chapter 32.
4. You cannot take the earned income credit.
5. You cannot take the exclusion or credit for
adoption expenses in most cases.
6. You cannot take the education credits (the American
Opportunity credit and the lifetime learning credit), the deduction for student
loan interest, or the tuition and fees deduction.
7. You cannot exclude any interest income from
qualified U.S. savings bonds that you used for higher education expenses.
8. If you lived with your spouse at any time during
the tax year:
a. You cannot claim the credit for the elderly or the
disabled,
b. You will have to include in income more (up to 85%)
of any social security or equivalent railroad retirement benefits you received,
and
c. You cannot convert amounts from a traditional IRA
into a Roth IRA.
9. The following deductions and credits are reduced at
income levels that are half those for a joint return:
a. The child tax credit,
b. The retirement savings contributions credit,
c. Itemized deductions, and
d. The deduction for personal exemptions.
10. Your capital loss deduction limit is $1,500
(instead of $3,000 if you filed a joint return).
11. If your spouse itemizes deductions, you cannot
claim the standard deduction. If you can claim the standard deduction, your
basic standard deduction is half the amount allowed on a joint return.
