Monument is a popular choice as it will make any planting in front of it pop. Given the narrow bed between the fence and the pool, is planting something you're considering? It will help to soften, and make the wall and fence less dominating.

Yes we are going a tropical garden

I see the reasons to use monument. But just remember that darker the paint it will attract the sun and will boil/bubble faster. Why not just paint it the same color of your house and make it flow all round

Looks looks great just worried ours in much higher and in a narrower space

I think it would look fine stella_bella_boo just remember to upkeep it

How about a test pot and have a go in a concealed area.

In every house we've had we have painted the fences kelp double strength - it's a very dark green with a fair bit of black in it. It actually makes the fence disappear into the background especaily once your garden gets established. Have also done black which looks very smart. I'm sure monument will achieve the same effect. Depending on the style of the rest of your garden you could get some of the very tall growing bamboos, non-invasive, and really anything you plant will drop a certain amount of litter. Pool scoop, ten minutes, no drama.