Hmm.Well,first,when we use the wrong terminology,its quite confusing for those trying to help.
The slide stop is the doohickey that holds the slide open and has the pin that goes through the link.
I think you mean the firing pin stop.
It is true a square bottom firing pin stop offers some more resistance to the slide.The earliest Browning design did it that way.The Army preferred the easier racking of the slide with the radius.
Consider the hammer pin takes more load.I think you can go either way.
How will you use your pistol?If you are not pursuing hot rod loads,or specific competition goals,especially as a relative beginner,I would respect all the work John Moses Browning put into getting it right.
So,what loads are you shooting?Pretty standard,or +P or crazy hotrod?
Unless you have good reason to go with a different mainspring(that is the one that drives the hammer) the book says 27 lb.I'm sure 24 would be fine.I have gone lighter.Same with the firing pin stop.If you are hotrodding,you can find some slide delay,at the price of racking the slide easily.Reducing the mainspring reduces the effect of the square corner,reduces your trigger pull,and slows lock time.
Or by "mainspring" do you mean recoil spring?I personally would not consider a 24 lb spring.The reason,what will tear up your gun is NOT the slide flying back.Its the slide flying forward.Too much violence with the barrel feet striking the slide stop pin,then transferring to the holes in the frame.Bad.
Think this way.Either use the factory recommended spring (16lb for a Wolff 5 in 45),OR,if you must,get a stock spring plus 2 lb,(Wolff makes an 18.5).In my Commander clone,I usea touch lighter than stock spring.With the loads I'm using,the slide stop was "iffy"last round.Lighter spring cured it.
Using your ammo,with the stock spring,load 1 round in the mag.Fire it.Does the slide lock back? If not,you need to order a couple of lighter springs.But if it does,great. For fun,go to the plus 2 spring.Does it lock back? Maybe?
OK,instead of typing it all out,I want my slide stop reliable.
Now,back to looking up your recommended spring,stock,for your 1911.(16 lb for a 5 in 45)To use hotter ammo,if I wanted to,I would go up 2 lbs,max. Like to an 18,maybe.
If I thought I needed more,I'd back off on my ammo.
Now you have solved your "dwell time" issue.If your mag springs are tired,or if you still need "dwell time" get wolff +10% mag springs.
But I stress,try to stay with the JMB design
Try not to vary more than one step.(Of couse,for light target loads,a lighter spring may be necessary) And no 24 lb recoil springs!