Some Brrrr financing questions

[Russell W.]

I'm hoping to further my understanding using the brrrr strategy from a numbers perspective and explain my current situation.  

Bringing all cash limits my buying power for the properties I'd like to get into which are multifamily units.  I've read others have obtained a loan at 20-25% which may or may not include rehab costs factored into the loan.  If the rehab costs are not included, the buyer funds it themselves.  

Typically using all your own cash, at time of refinancing if your arv is 70-75% of your acquisition price plus rehab costs you would get all your initial investment back. 

In this hypothetical all cash scenario my understanding is that your cash out refi would get your entire acquisition + rehab investment back:

ARV: 250k
Purchase Price: 170k
Rehab Costs: 17.5k
After cash out refi: 185,500 is retrieved to use on next property (75% LTV)

Now if I was to put  20% down on this same property instead of bringing the full purchase price to the table how does this affect my "After cash out refi" amount? (Let's assume that I am providing the rehab costs)

One question I have is regarding the "seasoning" period.  What do the finances look like during this time vs after the cash out refi? Is cash flow affected and what is the typical cost involved in the refinance?

 I have quite a bit of equity in my current home (140k) I could use to fund my first deal.  I would assume I am to treat this money as "cash" which then is retrieved if a 75% LTV is achieved, is that correct?  Until the cash out refi are you using the monthly cash flow to pay back the home equity loan?  It makes me nervous taking a home equity loan since it affects my current residence and ultimately my family.  It feels safer to use money I have saved specifically for investing but obviously using a home equity loan would give me much more leverage  .   I appreciate your help and insight!