I know hosts have included additional cleaning fees for violations as a deterrent.If none of these solutions work, you could look into completely independent HVAC systems for the two units, though that would be a bigger upfront investment.

That would be a helpful addition to your plan as you would further reduce your cost of living.Also don’t forget from that $600 you are planning on getting in cash flow you have taxes, insurance, maintenance, capex, and vacancy to consider.With two homes, you may want to keep that extra $20k as an emergency fund rather than spending it on a third property and then be left with no emergency funds.

Additionally, it's a good idea to connect with a Property Manager early on.

I racked up debt, at times putting expenses like property taxes on a line of credit.

A business line of credit through your LLC protects personal assets, builds business credit, and may allow interest deductions, but it might be harder to secure for a new LLC.

If I have several options, I would prefer a HELOC with no initial draw requirements (i.e. to establish a literal line of credit that I have no specific short term plans to use), i.e. not something like the better.com HELOC. 

So you have some great resources right off the bat, my additional Referrals would be too many :)

Rate will be highly dependent on loan size, credit score, LTV, location, and property type, as well as a few other factors.

Additionally, add in the ambiguity/risk of the due on sale clause or ramifications on the conventional loan of transferring the property from your individual name to an LLC - the economics don't make sense, and the headache isn't worth it even if it did, in my opinion!

Additionally, I'm hearing at meetups that this could extend to multi-fam under 4 units as well, although I haven't been able to confirm.I work exclusively with smaller investors in the multi family space and would be happy to chat more about it.