I think the last part of the coil number 5030 or 5032 refers to the number of windings.
Not sure if there would really be any noticeable difference changing to the 5030
And also I think actually the less winding the stronger the coil...

I may be mistaken though...

The coil numbers are just for Stern's internal part tracking.

A 5032 is 1080 windings of 22 gauge wire. A 5030 is 1100 windings of 23 gauge. The more important number though is resistance. 5032 is 4.3 ohm, and 5030 is 5.1 ohm. Higher resistance = weaker coil

I don't think you'd have any issue changing out for a weaker coil, but I can't really confirm it.

Hehe, so you heavily modified your pinball... and now it doesn't play right?

Pinball life sells a lot of stern flipper coils. Most will come with a diode, you'll need to clip the diode off before putting any of these in a new Stern.

I wouldn't hesitate to swap in a higher resistance flipper coil to see what it does to the power of the flipper unit. (shrugs) You can always put the 090-5032-ND back in. (ND = No Diode)

Note that there isn't a linear relationship to the ohms of resistance and the magnetic strength of the coil. Lower ohms is more powerful than higher ohms, and I'd just substitute and see if I like it instead of trying to figure out exactly what the ohms to the power of the flipper is mathematically.

Some pinball life Stern Flipper coils sorted by strength that you might explore:

090-5020 3.8 ohms (stronger than what you have!)
090-5032 4.3 ohms (what you have according to the RUSH manual)
090-5030 5.1 ohms (this is a standard flipper strength coil, but weaker than the 090-5032)
090-5025 9.6 ohms (I'd actually try this first, but I have this coil in stock!)
090-5041 13.8 ohms (probably quite weak, but might be powerful enough for you)

Pinball life coil page:

https://www.pinballlife.com/flipper-coils.html

Coil resistances page:

https://flippers.com/coil-resistance.html

Why change the flipper parts? I find the stock flipper plenty snappy.

This is why I don't recommend waxing new games. Wax doesn't protect a wooden playfield from a steel ball. It usually only makes the game harder to play.

Lots of good suggestions above. I would add double check your pitch setting and make sure you're at at least 6.5 degrees *between the flippers*. You should be able to go to 7 degrees or slightly more, but at least 6.5 between the flippers. Don't change any coils until you check your pitch first.

Wax rules for how it makes the game play faster without needing to jack the game up to some silly pitch.

Stern games are designed to be played at 6.5 degrees pitch. With the current design, if all four levelers are completely raised (not extended) and the floor is perfectly flat, the game will be at 6.5 degrees. No need to 'jack the game up' unless your floor is severely out of level.