It worked and I think it didn't take more about 200-300 MB of RAM, so in theory it should probably succeed on a device. However, it did take an absolute eternity on my desktop.
Code:
07/23/19-11:01:22 DEBUG CreDocument: set view dimen {
["h"] = 1872,
["w"] = 1404
}
07/23/19-11:01:22 DEBUG CreDocument: set status line property 1
07/23/19-11:01:22 DEBUG made tweak css:
[END]
07/23/19-11:01:22 DEBUG CreDocument: set style sheet: ./data/epub.css and appended content (0 bytes)
07/23/19-11:01:22 DEBUG CreDocument: set embedded style sheet 1
07/23/19-11:01:22 DEBUG CreDocument: set block rendering flags 0x7fffffff
07/23/19-11:01:22 DEBUG CreDocument: set render dpi 96
07/23/19-11:01:22 DEBUG CreDocument: set page margins 22 32 22 65
07/23/19-11:01:22 DEBUG CreDocument: set floating punctuation 0
07/23/19-11:01:22 DEBUG CreDocument: set txt preformatted 1
07/23/19-11:01:22 DEBUG CreDocument: set smooth scaling false
07/23/19-11:01:22 DEBUG CreDocument: set nightmode images true
07/23/19-11:01:22 DEBUG CreDocument: set font face Noto Serif
07/23/19-11:01:22 DEBUG CreDocument: set header font Noto Sans
07/23/19-11:01:22 DEBUG CreDocument: set font size 47
07/23/19-11:01:22 DEBUG CreDocument: toggle font bolder 0
07/23/19-11:01:22 DEBUG CreDocument: set font hinting mode 2
07/23/19-11:01:22 DEBUG CreDocument: set font kerning mode 1
07/23/19-11:01:22 DEBUG CreDocument: set space condensing 75
07/23/19-11:01:22 DEBUG CreDocument: set interline space 100
07/23/19-11:01:22 DEBUG CreDocument: set gamma index 15
07/23/19-11:01:22 DEBUG Hyphenation: no algo set
07/23/19-11:01:22 DEBUG CreDocument: set hyphenation left hyphen min 2
07/23/19-11:01:22 DEBUG CreDocument: set hyphenation right hyphen min 2
07/23/19-11:01:22 DEBUG CreDocument: set hyphenation trust soft hyphens 0
07/23/19-11:01:22 DEBUG Hyphenation: keeping current crengine algo: English_US.pattern
07/23/19-11:01:22 DEBUG CreDocument: requesting DOM version: 20180528
07/23/19-11:01:22 DEBUG CreDocument: set visible page count 1
07/23/19-11:01:22 DEBUG CreDocument: loading document...
07/23/19-11:08:33 DEBUG CreDocument: loading done.
07/23/19-11:08:33 DEBUG Hyphenation: updating for doc language it : English_US.pattern => Italian.pattern
07/23/19-11:08:33 DEBUG CreDocument: set hyphenation dictionary Italian.pattern
07/23/19-11:08:33 DEBUG CreDocument: set hyphenation left hyphen min 2
07/23/19-11:08:33 DEBUG CreDocument: set hyphenation right hyphen min 2
07/23/19-11:08:33 DEBUG CreDocument: set hyphenation trust soft hyphens 0
07/23/19-11:08:33 DEBUG CreDocument: rendering document...
CRE: document loaded, but styles re-init needed (possible epub with embedded fonts)
07/23/19-11:16:19 DEBUG CreDocument: rendering done.
A peculiar difference, because once opened it looks about the same at a glance. calibre concurs by opening it in some 8-10 seconds much like the other one.