CMYK issue: Krita or Cyan

[enrimoore]

First, thanks a lot for your hint

But, still totally unclear? English is not my language

If a conversion from, say Adobe1998 to Gimp srgb or to IECsrgb or to Nikon srgb4.... outputs files identical to the Adobe1998 file, all is perfect?

If, converting from any (eg. sRGB) RGB to CMYK you export in jpg and after a second you export the same CMYK converted
image in tiff, you now have one jpg file and one tiff file, right? Now, really you don't expect that these two CMYK files should be very similar?
If you don't agree on this, I am unable to clarify. If you agree, then discovering that those two files are totally different, is irrelevant?
For me it is a big surprise.

Sure, one can say, like myself initially: I could use the tiff, since it should be better.
But another person might say that it's like tossing a coin. Or anyway who knows what's happening? So how can it be reliable?

Or maybe I am just totally out of neurons, plus this work is terrible.
Or hopefully maybe I am still almost ok. But totally unable to explain something (odd) to somebody else

Thanks again anyway (if you happen to hear from someone who converted to CMYK and printed successfully, very grateful)
enri