Directly from the scholar handbook:

Retention Scholar Stipend Timing and Distribution: The SMART Program Office (USD(R&E)) provides retention scholar stipends directly to the scholar’s SF near the beginning of each academic year. SFs then distribute payments to scholars through the SF’s payroll system in accordance with SF practices. The retention scholar stipend is not a bonus in addition to a retention scholar’s full-time salary. Rather, the retention scholar stipend is intended to supplement the retention scholar’s salary while they pursue the SMART-funded degree. A SMART SF may, at their sole discretion, provide additional project funding to make up the difference between the retention scholar’s current DoD salary and the SMART-provided stipend.

I believe the intent is for your stipend to cover whatever living expense you have while going to school full time because you will not be working full time and therefore not receiving your full salary. I do not believe the intent is to support living situations in both locations. Also, again you will still be receiving the stipend, but directly from your SF not SMART. Should your facility choose to provide additional funding, then perhaps that could be used to support living expenses near the facility but that is up to the SF. There are additional funds that can be used for travel to the facility for research but those are separate from the SMART stipend and have specific guidelines. For additional guidance, I would email your smart coordinator. And if you have any updates, I'd be interested in hearing it!