I'd not be in any hurry to start mixing and matching parts.
First of all, S&W has made a revision to their 3rd gen .45 slides over the years. This can affect going from a single-sided manual safety assembly to an ambi assembly in the CS45.
For example, I bought my CS45 when the stainless versions were first released. All the CS guns of that time were produced with the standard single-side manual safety assembly.
When I first learned of the availability of the spring-loaded, decock-only ambi assembly, I wanted one for my CS45. I knew that it required some additional machining of the slide at the Performance Center so the assembly's spring could be anchored in the slide ... BUT ...
The new spring-loaded decocker was ambi-only, and
my CS45 was made to use the single side assembly. In order to install the decock-only ambi assembly they had to hand-file the angled slot/relief cut into the outside of my slide, on the right side, under where the ambi lever would be in the lowered position, because that relief cut was necessary in order to install or remove the ambi lever. (Normal for 3rd gen .45's of that production period, whereas the 9/.40's didn't require such a relief cut for the ambi levers to be installed/removed from the right end of the assembly.)
Here's a picture of a pair of 4513TSW's.
The top one is an original version (cutaway grip & 6-rd mags). Look at the slide just below the right end of the manual safety and you can see the machined relief cut that angles down and forward, which is required to give the ambi lever clearance to be installed & removed from the right end of the assembly.
Then, look at the bottom gun in the first pic, which is a current production version. See how the newer production slide no longer has (or requires) the angled machined cut on the right side of the slide below the ambi lever?
Here's a slightly larger pic of the original gun in the first pic, which might make the machined relief cut more visible.
Now, let's look at the right side of my older production CS45,
after it had been hand-modified by the PC to enable an ambi assembly to fit in the slide. Here it is as the bottom gun in a picture, below my 4513TSW. While the pic is blurry, you can see the shiny, hand-filed relief cut the PC gunsmith had to add to the right side of my slide, in order for the ambi assembly to be used on my older production CS45.
Here's another pic that shows it a bit better. Better focus and different light (ignore the grip, as I was just positioning a cutaway 4513TSW grip on the frame for another purpose).
So ... the ambi assembly (decock-only or standard manual safety) would not have been able to be installed on my older CS45 without the slide receiving the relief cut needed on 3rd gen .45 slide's of that production vintage.
Now, later production CS guns received ambi manual safeties and steel Novak Low-Mount sights (instead of the original plastic). So, while I haven't seen a newer production CS45 for a long time, unless the company started changing the slide design like they did with the 4513/66TSW's (eliminating the need for the relief cut on the right side of the slide) ... or, a particular CS45 was produced at the factory with an ambi safety standard (so you know the ambi lever will have proper clearance, whether or not it had the revised slide or the earlier relief cut) ... it's apparently not possible to simply "drop-in" an ambi assembly in an older CS45 that didn't come with one in the first place.
Also, in case that's not enough to consider ...
Replacing the manual safety assembly in any particular slide typically requires that the sear release lever be replaced in the frame. The lever usually requires "fitting" (hand-filing, maintaining the correct angle on the lever's foot in two planes) in order to produce the proper decocking "timing" in a 3rd gen TDA gun. This is VERY important for safe, proper decocking.
Replacing the spurless hammer with a spurred one (both being MIM)? Why? It's not a target/hunting pistol. Learn to use the DA trigger for the initial shot, with SA for subsequent shots (before decocking).
But yes, if you don't mind risking hammer bite if the spurred hammer is installed on the shorter
stirrup of the CS45 (not much of a frame tang on the CS or compact guns) ...
and the resulting assembly offers correct function during some normal armorer bench checks, meaning it must have the necessary tolerances to work with the existing sear & drawbar in any particular pistol ... it's possibly to switch a spurred hammer for a spurless one in many S&W TDA guns. Sometimes a particular hammer (or other part or assembly) might not fit in a particular pistol and allow for normal function, though, and trying another hammer (or sear or drawbar) might be necessary in that particular pistol.
Oh yeah, the ambi assemblies I have on-hand (both standard and spring-loaded) for my 9's are narrower than the ones in my .45's. You need the .45 ambi
lever in order to use the spring-loaded decock 9mm assembly in a 9mm slide, but the assembly body is itself narrower than that of the .45's. Another subject.
Just my thoughts.