I doubt increasing albedo would help much. Venus already has the highest albedo of any planet in our solar system (at 0.75, versus, for perspective, our moon's 0.12), due to its effectively-100% sulfuric acid cloud cover:

https://sciencing.com/albedo-planets-5203.html

https://www.universetoday.com/36833/albedo-of-venus/

Also, I doubt an insignificant chunk of ice (relatively speaking) could help cool it, or increase albedo.

I think the first order of business on Venus, if one wanted to colonize the surface (rather than colonize the atmosphere, which I think is doable), would be to "harvest" the gases of the atmosphere and thin it out to something more resembling Earth's.

It's not a question of cooling it. It went into a runwaway greenhouse effect (https://en.wikipedia.org/wiki/Runaway_greenhouse_effect) and it lacks hydrogen. All the hypothetical oceans oxygen bonded with carbon and hydrogen/water vapor was blown off by solar wind. The underlying cause was the loss of the protective magnetosphere.

Also, you are probably looking more to continent or small moon size quantities of ice (if that even works, and if the magnetosphere issue was somehow addressed) that metropolis.

Have you considered how much kinetic energy it would have, coming all of the way down the well from Saturn?

Enough to ionize the water molecules into H and O? Which returns hydrogen to the atmosphere, which is the missing component causing the runaway greenhouse effect?