This is so great! Please make some contemporary benches/planters if u can...

@BloodyPenguin
It is to hide the icon.

I tried "BuildingInfo+PlacementMode m_placementMode" "OnGround" . (by TPB's Guide) (Thanks Modtoos!)
So this park is placeable anywhere.
Unfortunately, in order for me to disable park's "missing road connection" icons, It is necessary to enter '0' value in 'Tourists' properties of asset editor.
However, The value of 0 sets the guests of this park to 0.
That is, nobody sits this park. It makes this park worthless.
Therefore, I entered '10' to the Tourists properties.
I got ugly icons instead of getting a guest at the park

Fortunately,If first place this on the roadside and then "move it!", the icon will not be displayed. (Probably...... I tested it only a few times)
If you know other good information, please let me know...

Why place on the roadside and then move it? You can just set placement style 'on surface' or 'on ground'

Well done. Really nice idea.