If your CD drive isn't one that CDRipper can set lower speeds on, like my Asus DRW-24B1ST, this free utility did it for me running on Windows 10.
You can find RimhillEx 1.09 at ht*tps://www.the-sz.com/products/rimhillex/
(I don't know the board policy on live links)
Some things to know:
This installs in your system tray there is no desktop icon.
8x speed is implemented at installation.
Right clicking on the tray icon and clicking on the drive name brings up the speed menu.
'Custom' speeds are by a slider control of kb/s.
There are only two 'Options', auto check for updates (which is why you have to give the program permission to access the internet), and check and reset speed every second.
The option to keep resetting the speed every second is what it took to overwhelm CDRipper's constant efforts to increase the drive's speed to Maximum during a rip.

What gave me hope that CDRipper can be modified to control speed on all drives was the fact that, before I installed any other software, it slowed down automatically when 23 bad frames in a row were encountered. This despite the fact that the option to manually set a slower speed during re-rips was also limited to Maximum speed on this drive. But CDRipper kept fighting itself the disk would slow down but before a frame could be completely read the program would try to speed up to Maximum again, then try to slow down again. So the program can already control the speed of a drive even if the drive 'says' Maximum only. I can see a need to continue to 'read' speed info from the drive, probably in kb/s, in order to make sure no options are available to increase speed beyond rated maximum.

Re-ripping the same disk using RimhillEx using one second continuous updates to 4244kb/s (approx. half of 48x 8468 kb/s = 24x, (necessary because RimhillEx's 'set' speeds are 1x, 2x, 4x, 8x, 16x, 32x, Custom, and Maximum, and I wanted to try 24x specifically), resulted in only two bad frames compared to 23 at full speed.

As I'm finishing this post I found one disadvantage: Although I had ripped a couple disks in a row without having to reset anything, when I came back a couple hours later after closing and restarting both programs I had to reset RimhillEx down from 48x again.