I'm just getting to a point to where I can consider starting to plan for my first property.

Time would be the biggest variable.Assuming the same repeatable services will have to be provided for STR & MTR, that are not provided for LTR, the costs may not be that different.Taking care of lawns, monitoring & paying utilities, taking calls, etc.Some services will be the same, but vary in frequency: cleanings, resupplying amenities, responding to inquiries, bookings, granting access, etc.

I plan to continue self-managing this property from afar.

How long do you plan on holding and what’s the requirements to renew the land lease?  

I don't have a property manager on them since I have 10% down, they take care of the place as though it's their own.

Basically, I'm planning to self-manage until my portfolio grows beyond my capability to do so.

Do you plan on doing the work yourself?

CAREFUL ..

Living in the US now, planning to go back to Spain within the next 5 years and I am wondering if anyone has experience using the BRrr strategy there.

Let's be careful about generalizations.