Hey MTSN. You may want to update your signature to include your new FICO 8 (which I think is now 819)
Incidentally, although your FICO 8 may have taken a 15 point dive, your EQ and TU mortgage scores likely took no significant hit at all. That's because the old FICO 04 model that EQ and TU use for their "mortgage" flavor does not include "total installment utilization" as a scoring factor. Your EX mortgage score likely did take a bit of a dive, probably one similar to what FICO 8 did.
Your decision to have no loans whatsoever to minimize DTI sounds smart given how high your mortgage scores are. Bear in mind that if you ever do decide to go with the Alliant SS loan approach, it will report with a very small "minimum payment" -- something like $9. Thus it won't have much effect on your DTI... unless your DTI without it is pretty close the border.