Seems to me that if an investor considering syndicates who does not have experience or contact with syndicators would do well to join with a group of investors experienced in investing in syndications and pay the membership fee to “ride” the knowledge of experienced investors in this field.  

Luckily coming from CA we have almost nothing you’d consider expensive.

However, ADUs still add substantial value by increasing the overall utility and potential income generation of the property.When it comes to appraisal, an appraiser will consider the added value of the ADU based on comparable properties in the area (comps) that have similar features, including ADUs if available.

I'm rehabbing the Espinho property so it's considered a flip, I guess.

With all of that said without know more specifics about what price points you're considering and location I'm going to Generalize1.

I'd consider doing some kind of cash out refi on the property at a number you're both comfortable pulling out, while still leaving $ for reserves to maintain the STR you currently have.

I am consider newbie in REI.

Their customer service is great.

Also considering a coastal STR in some of the smaller beach communities.That's great!

They might spot arguments or angles you hadn’t considered.