Vuescan 64 for Linux, as of the last time I used it, did not offer resolution above 4800. Have you tried this software in Linux?
Just checked, and Vuescan can indeed do 6400 PPI if "Transparency" mode is selected. If "Transparency 8x10" is selected, then you only get 4800 PPI as your max resolution.
I run Linux since ever with Vuescan for scanning. I have the V700. (two in fact, one for spare...)
Vuescan offers indeed 6400 dpi when "Transparency" mode is chosen (at least in "Professional" UI, I never user "Basic" and "Standard") but the scanning area doesn't cover 8x10, it's narrower. 8x10 coverage is possible only as "Tranparency 8x10".
example with a 8x10 sheet:
"Transparency":
"Tranparency 8x10":
that said, about resolution of the V700/V750/V800/V800/V850, there are many threads over the years at different places. Often it is said that it does a real ~2200 to 2400 dpi... "real" as "physical" as per hardware, and that other figures are internal firmware extrapolation.
A reference page is this one, here about the V800:l
https://www.filmscanner.info/en/EpsonPerfectionV800Photo.html
of course many people have been doing their own tests.
Just for illustration:
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for reasons too long to explain and that may be wrong, I scan BW as "BW negative" but with bits per pixel set as "48 bit GB", and save a "16 bit grey", as RAW in TIF format/container.
The 8x19 sheet seen in these screenshots of Vuescan gives the following sizes:
2400 dpi : 808 mb
4800 dpi: 3,2 gb
my photographic stuff is on a workstation with 48gb RAM and 2 Xeon 3,8Ghz quad-core each, so it's comfortable
a 1280px width 100% quality JPG of the 2400 scan after inversion of the negative in ColorPerfect grade 2 virtual printing:
a 100% zoomed crop of the first beast in the center, this here is not a JPG but a lossless PNG chunk of the original RAW:
by the right egde on the whole image there's a black thombstone, 100%, same, lossless PNG :
now, from the 3,2 gb 4800 dpi scan. crops of the same, at 67% instead of 100% just for practical purpose of not providing too big image here:
on the thombstone of Svend Lien there's not so much difference in the resolution of " födt" and "död" ....
now, if I am happy with the narrower scan that can be made as "Transparency" at 6400dpi, which is possible in this case, because I can keep the church and leave part of the sky and of the foreground. Image ratio is of course elongated then.
a web rendering at 1280px reduction in 100% JPG:
a 100% crop of the beast, same, on the original RAW, saved as PNG. heavy file for web ~ 1mb, so you need a good internet speed:
and Svend Lien: