Reevaluate font in seed backup

[andrewkozlik]

Is your feature request related to a problem? Please describe.

We recently had a user who misread the word "guest" during Shamir backup and noted it down as "quest". Naturally, the user couldn't recover their wallet, because the firmware did not accept the word "quest", which is not in the SLIP-0039 wordlist. When designing the SLIP-0039 wordlist we took care to eliminate the simultaneous presence of words that are similar or can be misread, e.g. "clock" and "dock", but that doesn't stop the user from misreading the word shown on the screen and noting it down incorrectly.

Describe the solution you'd like

Consider showing the recovery words during backup in uppercase to improve legibility.

Technically the words for both SLIP-0039 and classic BIP-0039 backup are defined in lowercase. We would need to make sure that this doesn't cause some sort of interoperability problems for users.

Describe alternatives you've considered

Increase the font size in seed backup, e.g. simply double-sizing the font.

Additional context

Some mockups to show the difference:

[prusnak]

The issue at hand is more about the legibility of a written backup, not necessarily about how the words look on the display.

If your handwriting is not perfect, it might be hard to distinguish g/q and cl/d, while uppercase letters might pose different challenges.

[Hannsek]

@prusnak what kind of challenges do you have in your mind?

[prusnak]

@prusnak what kind of challenges do you have in your mind?

What I meant is that even when we show the word in upper-case (CLOCK), a user might write it down in lower-case (clock) and confuse it with "dock" when reading it back.

In other words, the fact we use upper-case or lower-case letters on device, it does not necessarily mean that users will use the same case while writing it down.