A few more tips
A h00 byte signals the end of a message. Do not change any h00 bytes.

The zero-byte, marking the end of a message, is selected. It comes directly after a new-line pair of bytes.

There is a message that starts at address h3C1A8 (byte number 246,184) that includes the two ASCII characters "%d". These characters are replaced by a number when the bootloader displays this message. You should include these two characters somewhere in your own message. Although I have not noticed any yet, there may be other messages with a similar combination of characters.

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- Robbi-985 aka SomethingUnreal