My custodian does not have a money market or similar sweep account to keep idle cash earning.

@Michael James Hamlin I'm a former tax accountant/business consultant turned fix n flipper and investor friendly agent. 

I’ve got her dealing with 8 properties which have individual accounts.

Additionally, we have a decent amount invested in retirement accounts, which we plan to continue building over time.As part of the move, we’ll be purchasing a larger home.

No one accountant is an expert in all areas in the tax code, so best to figure out what you want first in the world of real estate and then dive deeper there. 

Anyone answering is not responding as a Tax accountant, Insurance expert or as a Financial advisor.  

I once made the mistake of chasing multiple listings at once, which turned into a disaster.When I shifted my focus to serving one client at a time with honesty, integrity, and accountability, referrals started coming in without any marketing.

I have some of the required funds in a HYSA, but will most likely need to draw from another account and I'm curious which method is the most efficient in terms of taxes/capital gains, penalties, loan repayments, etc.Based on my previous transactions in the market, I estimate ~$45k cash to close: $20k for the down payment, $15k for closing costs and prepaids, and $10k of starting reserves.

While no property is too big or too small for a cost segregation study, it’s important to speak with your accountant to ensure the benefits outweigh the cost of the study.

If you have a high 7 rate then it might be beneficial in the long run to pay it down if you don't want to put it in a 4% savings account or CD.