ReShade 6.0 is out. One exciting thing it's introduced is the ability to use MSAA (for example, Edge Smoothing in TS4) in dx9 games without breaking the depth buffer. This is dependent on your gpu/driver compatibility, so if yours is old it may still not work, but it's worth a shot! (In true 'amoebae has an old computer' style, it does not work for me lol)
I updated to 6.0 last night in TS4 and everything else works as expected. One weird quirk in dx9 games seems to be that shaders are taking longer to compile. It can seem like everything has frozen or crashed. But be patient, wait longer than you think you'll have to wait, and it should eventually load them all.
Once it's loaded them once, they'll be cached and should load quicker next time. If you hotsample, you'll need to sit through that long initial load for each new window size.
There are a couple of things you can do to speed things up a little bit if it's really unbearable.
If you have any compiling errors in red at the top of your shader list, rather than just leaving them there remove the shaders. Non-compiling shaders always slow things down, even once everything is cached.
Also, before hotsampling you can check the option to only load active shaders. That way your hundreds of other shaders won't load, and it'll cut down the time quite a bit. Obviously, you can't then tweak any of those non-loaded shaders, so you'll have to disable that option if you want to use anything else. You can still tweak the shaders you have loaded though, unlike in Performance Mode, which stops you from changing anything at all.
I don't recommend installing any of the new addons offered as part of the installation process unless you know what they are and you know how to use them. Most of them are additional functionality for shader and addon authors. Others, like Shader Toggler and REST can be useful in TS4 but you need to know how to use them. If you don't already know, don't worry about them, you can ignore them entirely.