So... 4.2.xxxx was released for Kobo H2O today, including the 32bpp change, and... experiment2 worked out of the box for me , no additional changes. Not sure why it didn't work for your KA1.
screensaver.cfg scanline values for H2O English 4.2.8432:
Code:
#
# Standby scanline autodetected Thu Feb 9 21:22:00 CET 2017
# If this value does not work, remove it so it will be re-detected.
#
standby=1286:ffffffff*ff000000*fff8f8f8ffffffff*ffa9a9a9ff000000*ffffffff*ff727272ff000000*ff3e3e3effffffff*ffa3a3a3ff4f4f4fff090909ff000000*ff090909ff585858ffc8c8c8ffffffff*ffa3a3a3ff4f4f4fff090909ff000000*ff090909ff585858ffc8c8c8ffffffff*fff7f7f7ff909090ff3c3c3cff000000*ff020202ff838383ffffffff*ffd2d2d2ff525252ff141414ff000000*ff111111ff6a6a6affe0e0e0ffffffff*ffdededeff7c7c7cff2a2a2aff000000*ff010101ff757575ffffffff*ffeeeeeeff888888ff373737ff000000*ff060606ff878787ffffffff*ffd2d2d2ff696969ff111111ff000000*ff0b0b0bff5b5b5bfffafafaffffffff*ffb5b5b5ff5e5e5eff0e0e0eff000000*ff121212ff313131ff7f7f7fffe0e0e0ffd7d7d7ff8d8d8dff424242ff000000ffc2c2c2ffffffff*
#
# Poweroff scanline autodetected [1] Thu Feb 9 21:22:28 CET 2017
# If this value does not work, remove it so it will be re-detected.
#
poweroff=1286:ff000000*ff2c2c2cffffffff*ffcdcdcdff000000*ff686868ffffffff*ff070707ff000000*ff575757ffa6a6a6fff3f3f3ffffffff*fff2f2f2ffb5b5b5ff4b4b4bff000000*ff383838ff969696ffecececffffffff*ffddddddff4d4d4dff000000*ffe4e4e4fff8f8f8ffffffff*ff6a6a6aff000000*ff3c3c3cffd9d9d9ffffffffffedededff3b3b3bff000000*ff5c5c5cffb0b0b0fff6f6f6ffffffff*fff6f6f6ffa7a7a7ff373737ff000000*ff111111ff777777ffc8c8c8ffffffff*fffcfcfcff888888ff000000*ff6a6a6affe9e9e9ffffffff*ffddddddff393939ff000000*ff5c5c5cffb0b0b0fff6f6f6ffffffff*fff6f6f6ffa7a7a7ff373737ff000000*ff555555ffadadadfff6f6f6ffffffff*fffefefeffd9d9d9ffacacacff505050ff000000ffffffff*ff5a5a5aff000000*ff575757ffa6a6a6fff3f3f3ffffffff*fff2f2f2ffb5b5b5ff4b4b4bff000000*ff030303*ffabababffffffff*ffc4c4c4ff030303*ffabababffffffff*ffc4c4c4ff030303*ff000000*