I'm not sure what Boyd means by "low resolution"
It's just simple math. USGS topos have a scale of 1:24000, I am making topo maps at a scale of 1:3000, which is 8x higher resolution. Here's a comparison showing the exact same area, with my map at the top.
Notice how the USGS buildings are just square blocks that are bigger than the real ones. My buildings were hand-traced from aerial imagery. This is a flat area so no elevation contours appear on the USGS map. I used 3 meter LIDAR DEM to create high resolution contour lines (1 meter LIDAR is now available too). Also notice how fat the unpaved roads. The line weights on my map are very close to the actual width of an upaved road. The higher resolution on my map also allows the inclusion of property lines. I am also using forest shading and wetland data with native scale around 1:12000, which is twice as accurate as a USGS 24k maps.
Like I said, I really admire the craftsmanship that went into the USGS topo's. But modern devices are capable of using much more accurate data.

Wow - your procedure for making maps is very complicated! The screenshots look very nice though.

Like most things, better tools make the job easier. I invested in a copy of GlobalMapper many years ago when the price was still reasonable. Have not updated it for many years, it has gotten very expensive since a big company purchased the software. But Globalmapper will directly open the geoPDF files from the USGS and you can re-project them as desired with a couple mouse clicks. Another mouse click will remove the map "collar".
Personally, I really dislike hill shading on a USGS map, but if I wanted it then it's very simple to download DEM at any resolution from the USGS 3DEP website. Again, just a few mouse clicks will apply the shading to the map and you can tweak lots of rendering parameters in the preferences.
So all of that is very straightforward. Where I spend my time is color-correcting the quads to match each other. There's a huge color variation in the different quads, some of them are yellow where they should be green! I use photoshop to fix this, which involves a few extra steps.
It is also tedious to match the edges of each quad to the adjacent ones. Again, because the accuracy is rather low by current standards, the maps don't overlap all that well. Takes some trial and error to get the best stacking arrangement.
After I'm happy with the finished seamless map, I need to convert my GeoTIFF file to a tiled format that can be used with Mobile Atlas Creator. This is rather involved so I won't go into it here. But you can see or download one of my historic topo's to see the results:
https://boydsmaps.com 