The OS requirements seem steep. It's not clear if it's TOS 4.04 only...
It seems you need at least a 020 to view PDF's on the Mac platform too, at least for Acrobat Reader 2.0 and I think you need Reader 3.0 (maybe 4.0?) for PDF v1.3 files. Reader 3.0 was the last on the Mac to run on 68k architecture, so probably needs at least an 020 if not an 030.
So maybe reading of PDF's is only practical on TT's and Falcons...
Good to know!
1977 VCS Heavy Sixxer (Boxed)
1990 Atari 1040STE, 4MB, UltraSatan, TOS 2.06, TT Touch -> Atari SC1435 Colour CRT Monitor
1991 Atari TT030, 2/16MB, Int 8GB Gigafile, TOS 3.06, CaTTamaran Accelerator -> 1991 Atari TTM195 19" Mono CRT Monitor
1993 *** NEW! *** Atari Falcon030, 14MB, 84MB HDD, TOS 4.04
Amiga 500, Win 3.11 PC, Several old Macs, Newton, SGI Indy, much more and counting!