You can increase various settings but I don't expect there to be a huge visual difference between the default SMAA preset and any custom settings, there's only so much that post-process AA can do although it does make a improvement in many games even if it can't get rid of aliasing entirely.
(You can combine it with Nvidia DSR / AMD VSR if you have the hardware for downsampling but there's a pretty hefty performance hit.)
The current default ReShade SMAA settings are also already pretty much set to the highest supported besides corner rounding (Since it does affect text and such more noticeably even when using low values.) besides that enabling predication and using color edge detection are the only things I can thing of that might maybe provide some improvement though predication will require the game to have depth buffer access for ReShade so you can't use certain settings, mainly MSAA whether in-game or driver forced.
(Some games also make use of logarithmic and/or reversed depth buffers but there are compatibility settings for all of that so it's not a huge issue as long as ReShade is able to capture the depth buffer.)
The easiest for understanding the settings more in-depth would be to open SMAA.fx or maybe it was SMAA.h, anyway it's the source SMAA file and it comes with explanations for almost all settings and how they work along with suggested presets.
Only other improvement would be some way to get SMAA T2X or 4X functional but from what I've come to understand that wouldn't be easy at all from a generic injector.
EDIT: Oh yeah the in-game UI of the ReShade 3.0 beta (#4 I think the latest public release was?) anyway it allows for changing the shader settings on the fly so you can more easily check to see what the different values affect and how they affect whatever game you are using it with, less shader heavy generally older games will probably be easier to test with as you'll get more noticeable results without or at least with less shader and specular aliasing.
Those settings look fine to me. The only thing left to do would be to verify that predication is working properly with the depthbuffer, and to crank corner rounding as high as you can stand. Yeah, corner rounding affects text, but I found smaa doesn't really do a whole lot with corner rounding set to 0.
In many games, I've had good success with removing jaggies using the following shaders in this order:
fxaa (0 subpix)
lumasharpen (low value between .2 and .35 depending on whether I actually want it sharper than before fxaa was applied or not)
smaa (with between 50 and 75 corner rounding, and predication)
It kinda turns text into cartoonish bubble fonts, though. heh. Still totally readable because they're not blurry.