The monthly payment on a HELOC is over 300 more per month because of the 20 year repayment.

It all depends on your unique situation.  

I put together a re-payment plan with her, which she signed.

The repayment terms for a 401k participant loan are equal monthly/quarterly payments of principal and interest (typically prime plus 1%) over a 5 year term (longer if used to acquire your principal residence).Please note that if you take a full $50,000 and then pay back the loan, you can't take another $50,000 until 12 months after the first loan was fully paid back.Per the loan offset rules that went into effect with the 2018 Tax and Job Act: if you leave your job and the loan is current at the time you leave your job but then the loan goes into default because you left your job, you will have until your tax return deadline (including any timely filed extension) to make the loan current by depositing the outstanding balance into an IRA (and thereby avoid the taxes and penalties that would otherwise apply).Please keep in mind the multiple loan rules:Under those rules, the sum of the balances of a participant's outstanding 401k loans under a single 401k plan (using the highest outstanding balance of each loan over the last 12 months) can't exceed 50% or $50,000 whichever is less.

I'll be sending them an Invitation to Repayment Plan Monday (tomorrow) that will outline the amount owed over the next 3 months, which seems to be the standard timeline.

Texas is a unique state that it does not have a state income tax. 

-are unique in that they develop their own gear alongside the brands for which they are also a supplier.

It has extremely unique capabilities that directly support national security.

The question is not "exactly what will my ROI be", it's more about the uniqueness of the situation and the opportunities it affords.

The repayment terms for a 401k participant loan are equal monthly/quarterly payments of principal and interest (typically prime plus 1%) over a 5 year term (longer if used to acquire your principal residence).Please note that if you take a full $50,000 and then pay back the loan, you can't take another $50,000 until 12 months after the first loan was fully paid back.Per the loan offset rules that went into effect with the 2018 Tax and Job Act: if you leave your job and the loan is current at the time you leave your job but then the loan goes into default because you left your job, you will have until your tax return deadline (including any timely filed extension) to make the loan current by depositing the outstanding balance into an IRA (and thereby avoid the taxes and penalties that would otherwise apply).Please keep in mind the multiple loan rules:Under those rules, the sum of the balances of a participant's outstanding 401k loans under a single 401k plan (using the highest outstanding balance of each loan over the last 12 months) can't exceed 50% or $50,000 whichever is less.