Does this mod work like the Simple Silicon Mod? I am still using that mod for version 1.1. (I show how to update it to work for 1.1 in the comments there. Last official update was for v0.18 of Factorio.)

It works very similarly. I'd say this mod is less deep but more wide than Silicon Quartz so it is about as hard.
-In Simple Silicon, you turn stone + water into Quartz, which is smelted into Silicon. Silicon is used for Silicon Wafers and Solar Cells, which are used in Red/Blue Circuits and Solar Panels respectively.
-In Silicon + Quartz, you turn stone into sand (which is smelted into Glass for several other recipes). Then you can turn sand into Quartz, which is smelted into Silicon. Silicon is used for Red Circuits and Solar Panels directly, while it is turned into a Silicon Wafer for Processing Units.

The Silicon wafer recipe in this mode is much harder than the one in the Simple Silicon mod, requiring steam. Glass is used in the Solar Panel recipe so it is about as hard. However, there are generally fewer intermediate products.