Need advice on a/c cooling 2nd floor

I recently purchased a two story 2000 sq ft house in Ohio that was built in 1971 and I had a lot of work done on the a/c including a new unit and filter system. That being said, my main concern is getting cooling up to the 2nd floor in the heat of summer. There look to be a decent amount of supply and return vents on both floors.

It’s not yet hot enough to test but I’d like to have some sort of game plan in advance – It appears that mostly what I’ll be able to do to help is use ceiling fans and/or block certain vents in the summer. That being said, I came up with a few ideas – some extreme as I tend to think in extremes:

1. Block most or all of the supply vents on the first floor forcing more air to go to the 2nd floor
2. Block most or all of the return vents on the first floor forcing the 2nd floor returns to pull the heavier cool air up to the 2nd floor.
3. Combine 1 and 2 (definitely the most extreme).

So my questions are basically twofold:

In your best guess, what would be the best option of those 3 and are there any other viable options than what I’ve listed without tearing open walls and adding ductwork?

I understand if you block a lot of vents, it could put strain on the system and cause damage. How severe could the damage be? I ask because, if it works in getting more cool air to the 2nd floor, it may be worth it for me to pay more for routine maintenance and/or repairs depending on the cost. If i go that route, is there any specific maintenance i should have done on a regular basis?

Any advice or help would be appreciated.

source https://hvac-talk.com/vbb/threads/2228494-Need-advice-on-a-c-cooling-2nd-floor?goto=newpost