OK, Foster type slugs are sized to go through any choke, "common knowledge" to the contrary. The better accuracy is usually from improved cylinder, but that may vary. The only way you'll find out is to try it. The lead won't hurt the choke.

Steel shot is another matter. If the barrel steel is too soft, it'll batter the choke out of it over a period of time, possibly scar the bore.

BTW, when you buy a gun doesn't matter, it's when the gun was made. I've bought new guns that I've later identified as being 7 years old by the manufacturers coding. It's also not unusual for manufacturers to use up an oversupply of older parts on new production, especially if they're shipping to low cost contract buyers.