Rule of thumb for engineered wood acclimatization

What rule of thumb works best for you when targeting the right temperature and moisture to acclimate engineered floor on concrete slab?

The flooring installation guide says run a/c between 65-75F and keep humidity between 35% - 55%.

However, I live in a humid area. My 2.5 yrs of measurements, the temperature is 65–75F, and humidity is 40-70%.

Is it better to go by the manufacturer or go by the home’s temperature and humidity range? Thanks!

If the slab doesn't have a really good moisture barrier under it, you need to know how much moisture is coming out of the concrete.
There are some really good moisture limiting coatings and adhesives made these days, but I'd still want to know what the moisture level is in the concrete or coming out of it.
This isn't a basement, right? How old is the house? I assume you are near the northern coast?
Concrete is a totally different animal when it comes to wood flooring so you need to proceed with caution.

You shoot for the median rh over the course of a year. So in your case I would acclimate it to 50% depending on the woods specific gravity, the woods moisture content should be around 9% @ 70F.

It’s a 2nd floor condo in SoCal, around nine years old. It currently has engineered wood that’s glued directly onto concrete. Thanks.

It's probably not concrete, it's just gray a gray colored leveling compound that's used as an underlayment material. It's base is Gypsem. Gypcrete is a common one. It's used a lot in condos, apartment and retirement complexes. When poured, its so thin it flows like thick water and seals the perimeter against the sheetrock, creating a fire barrier should an apartment below catch fire. It's also a sound deadener and it does make the floor very flat which is good.
When your current wood is removed, the Gypcrete or whatever will be probably damaged to some degree, because the material is a lot softer than concrete.
You don't need to worry about measuring moisture as I replied to your initial question. Engineered is a lot more stable than solid wood, so that's in your favor.
I gotta run, so I'll post this and read it later.
https://www.usg.com/content/dam/USG...on-guidelines-for-damaged-gypsum-en-CB822.pdf

Scroll down to pages 4 through 8. https://www.fpl.fs.fed.us/documnts/fplrn/fplrn268.pdf