Attached to this post is the 2.20beta for all hwOS2 devices. It has several new features and some bugfixes compared to the 2.15: (New since 2.18beta)
NEW: Third and fourth logbook page per dive showing Gaslist and Setpoints in standard font size
BUGFIX: several minor graphic issues in logbook fixed
BUGFIX: Rare button issues in OSTC Plus hardware
BUGFIX: Compass sensitivity for newer models
BUGFIX: PSCR mode showed bailout gaslist instead of diluent gaslist
BUGFIX: PSCR mode "Better Gas" showed bailout gases instead of diluents
NEW: More customviews in surface mode for PSCR mode
NEW: Last Dive customviews in surface mode with divetime, depth and interval
BUGFIX: Reset to MOD in Diluent Menu did reset Setpoint change depth
NEW: Two ppO2 max settings. One for travel/bottom and one for deco gases
BUGFIX: Lost Diluent now possible in CCR and PSCR mode
NEW: ppO2 blinks in sensor mode when min/max boundaries are hit
CHANGE: Show actual GF (Not relative) in custom views in dive mode
BUGFIX: Do not check ppO2 for disabled gases
CHANGE: Apply safety margin parameters to both models (GF and non-GF)
BUGFIX: Impossible fixed-ppO2 (e.g. 1,6bar in 3m) used for tissue calculations
BUGFIX: Menu tree cleaned up (Exited to CCR menu from simulator settings)
BUGFIX: Do not show GF in divemode for non-GF deco mode
BUGFIX: Skip MOD Test for CCR in Sensor modes (OSTC cR and OSTC3 only)
CHANGE: Swap positions of ppO2(O2) and ppO2(Dil) in customview 10 on screen: "left = lean" and "right = rich"
BUGFIX: A wrong configured gas was suggested as "Better gas" on the configured depth even if this resulted in a ppO2 high or low condition
BUGFIX: O2 as diluent in CCR caused wrong calculations (Deco, EAD, END) in less then 6m depth
BUGFIX: Ignore "Toggle GF" Menu entry (in divemode) when using the non-GF deco mode
BUGFIX: Minor dive mode layout fixes in CCR Mode
CHANGE: Minor German language fixes
NEW: Warning for Diluent beeing out of safe ppO2 range in CCR modes
NEW: New Customview 9 in OSTC cR or OSTC3 shows mV readings after Sensor calibration
Weekend is coming, so please post some feedback on Monday

regards,
Matthias