Back to no.1 computer 
First a bit of history: This is Gimp 2.8 where waves is an actual binary plugin which you find in /usr/lib/gimp/2.0/plug-ins/
And you can see where those Gimp 2.10 values come from. I did look and an older Gimp 2.10 (appimage) and wavelength is 0.1 to 50 not 0.1 to 100 as with latest Gimp. The devs must have tinkered with it sometime. The problem with that is it is a GEGL compatibility plugin and does not exist as a separate binary plugin.
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If you want to use the GEGL parameters 0 to 1000 then you might have to abandon scheme and see if you can get python 2 and gimp-python working. Maybe using a flatpak or an appimage version.
This using a utility plugin and GEGL values for waves.
First a bit of history: This is Gimp 2.8 where waves is an actual binary plugin which you find in /usr/lib/gimp/2.0/plug-ins/And you can see where those Gimp 2.10 values come from. I did look and an older Gimp 2.10 (appimage) and wavelength is 0.1 to 50 not 0.1 to 100 as with latest Gimp. The devs must have tinkered with it sometime. The problem with that is it is a GEGL compatibility plugin and does not exist as a separate binary plugin.
-----------
If you want to use the GEGL parameters 0 to 1000 then you might have to abandon scheme and see if you can get python 2 and gimp-python working. Maybe using a flatpak or an appimage version.
This using a utility plugin and GEGL values for waves.