Ok so I was playing around with the dtb files today to test others in the search for a working heartbeat led. This is what i've found.
meson64_odroidc2.dtb Can load up with working HDMI and heartbeat.. But has a recurring error
[ 78.598264] i2c i2c-1: [aml_i2c_xfer] error ret = -5 (-EIO)
[ 78.602108] i2c i2c-1: token 1, master_no(1) 300K addr 0x51
[ 78.607810] rtc-pcf8563 1-0051: pcf8563_get_datetime: read error
[ 80.441991] i2c i2c-1: [aml_i2c_xfer] error ret = -5 (-EIO)
[ 80.445828] i2c i2c-1: token 2, master_no(1) 300K addr 0x51
[ 80.451523] rtc-pcf8563 1-0051: pcf8563_set_datetime: err=-11 addr=03, data=31
[ 80.597084] i2c i2c-1: [aml_i2c_xfer] error ret = -5 (-EIO)
[ 80.600936] i2c i2c-1: token 1, master_no(1) 300K addr 0x51
[ 80.606637] rtc-pcf8563 1-0051: pcf8563_get_datetime: read error
So if someone has ideas or a guide that is better for converting the dtb>dts>dtb That would be great and we might be able to get everything working as intended.