Add symbols of playing card suits ♠ ♥ ♦ ♣

[BrainInJar]

Hello everyone!
Thank you for an awesome free and open-source font!

It would be nice to have a full set of symbols of playing card suits in Inter: ♠, ♥, ♦ and ♣. Currently, the only available symbol is "♥".

I'm completely ignorant about fonts, but after several days of suffering, with the help of FontForge I've somehow managed to add suits symbols to Inter from the font Noto Sans Japanese

But there were way too many warnings and errors on editing and saving like these:
The glyph named Iota is mapped to U+0196.
But its name indicates it should be mapped to U+0399.
The glyph named uni021A is mapped to U+0162.
But its name indicates it should be mapped to U+021A.
The glyph named rrthook is mapped to U+E05D.
But its name indicates it should be mapped to U+027D.
The glyph named rdescend is mapped to U+E05E.
But its name indicates it should be mapped to U+027C.
The glyph named uni0326 is mapped to U+F6C3.
But its name indicates it should be mapped to U+0326.
The glyph named uni25CE is mapped to U+0298.
But its name indicates it should be mapped to U+25CE.
The glyph named uni05DA is mapped to U+02AA.
But its name indicates it should be mapped to U+05DA.
The glyph named uni05DD is mapped to U+02AD.
But its name indicates it should be mapped to U+05DD.
The glyph named uni05E5 is mapped to U+02B5.
But its name indicates it should be mapped to U+05E5.
The glyph named uni200D is mapped to U+FEFF.
But its name indicates it should be mapped to U+200D.
The glyph named uniFB47 is mapped to U+02DF.
But its name indicates it should be mapped to U+FB47.

And I have no idea what they mean and how to fix them.

And there's a question of licensing; I don't want Rasmus or Google to sue me for combining their fonts.

Due to all these things, I'm afraid to use this modification of Inter on my website.

But in my humble opinion, it looks pretty nice:

So, is there hope that in the future, someone more knowledgeable than me will add ♠, ♦ and ♣ to Inter?

Many thanks!

[kenmcd]

And there's a question of licensing; I don't want Rasmus or Google to sue me for combining their fonts.

Both fonts are OFL licensed.
So you can basically do whatever you want with them - except sell them as your own.
Modifying them to use on your website is fine.

But there were way too many warnings and errors on editing and saving like these:

FontForge is apparently a bit confused.
Some of those appear to be alternate forms from stylistic sets.
Some appear to be mapping alternates to the PUA (Private Use Area) - which was continued to support some specific users or applications.
You can ignore those warnings.

And I have no idea what they mean and how to fix them.

"Missing Points at Extrema" is mostly related to variable fonts.
Generally, having points at the extrema (farthest top, bottom, left, right) helps the interpolation work better. But, it is not required, and may sometimes not be desired.
It is up to the font designer.

I would hope these warnings are explained somewhere in the FontForge docs.

Due to all these things, I'm afraid to use this modification of Inter on my website.

Make a test page and try it out first.

[BrainInJar]

Thank you very much for your reply!