The width of 凰 (U+51f0) in Sans JP looks odd.

Problem

IBM-Plex-Sans-JP

In some weight, the glyph width of 凰 (U+51f0) is not 1000. (Other Kanji glyph width are 1000)

weight	width
Bold	1000
Text	1001
Thin	1000
Light	1001
Medium	1001
Regular	1002
SemiBold	1000
ExtraLight	1001

Are they expected or bug?

Check script and output

Download TrueType.zip from Release (v6.3.0)
Save following python script as test.py
Excute fontforge -lang=py -script test.py

import fontforge

TTF_FILES = [
    "TrueType/IBM-Plex-Sans-JP/unhinted/IBMPlexSansJP-Bold.ttf",
    "TrueType/IBM-Plex-Sans-JP/unhinted/IBMPlexSansJP-Text.ttf",
    "TrueType/IBM-Plex-Sans-JP/unhinted/IBMPlexSansJP-Thin.ttf",
    "TrueType/IBM-Plex-Sans-JP/unhinted/IBMPlexSansJP-Light.ttf",
    "TrueType/IBM-Plex-Sans-JP/unhinted/IBMPlexSansJP-Medium.ttf",
    "TrueType/IBM-Plex-Sans-JP/unhinted/IBMPlexSansJP-Regular.ttf",
    "TrueType/IBM-Plex-Sans-JP/unhinted/IBMPlexSansJP-SemiBold.ttf",
    "TrueType/IBM-Plex-Sans-JP/unhinted/IBMPlexSansJP-ExtraLight.ttf"
]

def test(range_):
    for codepoint in range_:
        try:
            glyph = font[codepoint]
            width = glyph.width
            if width != 1000:
                unicode = glyph.unicode
                name = glyph.glyphname
                print(hex(codepoint), hex(unicode), name, width)
        except TypeError:  # No such glyph
            pass

for ttf in TTF_FILES:
    font = fontforge.open(ttf)
    print("\n>>>", ttf)
    test(range(0x2e8e, 0xfa6a))
    test(range(0x20b9f, 0x2f920))
    test(range(0x110161, 0x110326))

Copyright (c) 2000-2023. See AUTHORS for Contributors.
 License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
 with many parts BSD <http://fontforge.org/license.html>. Please read LICENSE.
 Version: 20230101
 Based on sources from 2023-01-01 05:27 UTC-D.
The following table(s) in the font have been ignored by FontForge
  Ignoring 'DSIG' digital signature table

>>> TrueType/IBM-Plex-Sans-JP/unhinted/IBMPlexSansJP-Bold.ttf
The following table(s) in the font have been ignored by FontForge
  Ignoring 'DSIG' digital signature table

>>> TrueType/IBM-Plex-Sans-JP/unhinted/IBMPlexSansJP-Text.ttf
0x51f0 0x51f0 uni51F0 1001
The following table(s) in the font have been ignored by FontForge
  Ignoring 'DSIG' digital signature table

>>> TrueType/IBM-Plex-Sans-JP/unhinted/IBMPlexSansJP-Thin.ttf
The following table(s) in the font have been ignored by FontForge
  Ignoring 'DSIG' digital signature table

>>> TrueType/IBM-Plex-Sans-JP/unhinted/IBMPlexSansJP-Light.ttf
0x51f0 0x51f0 uni51F0 1001
The following table(s) in the font have been ignored by FontForge
  Ignoring 'DSIG' digital signature table

>>> TrueType/IBM-Plex-Sans-JP/unhinted/IBMPlexSansJP-Medium.ttf
0x51f0 0x51f0 uni51F0 1001
The following table(s) in the font have been ignored by FontForge
  Ignoring 'DSIG' digital signature table

>>> TrueType/IBM-Plex-Sans-JP/unhinted/IBMPlexSansJP-Regular.ttf
0x51f0 0x51f0 uni51F0 1002
The following table(s) in the font have been ignored by FontForge
  Ignoring 'DSIG' digital signature table
警告: 'name' テーブルの Mac と Windows の項目で文字列 Family が言語 English (US)
      版において一致しません.
 Mac の文字列: IBM Plex Sans JP Smbld
 Windows の文字列: IBM Plex Sans JP SmBld

>>> TrueType/IBM-Plex-Sans-JP/unhinted/IBMPlexSansJP-SemiBold.ttf
The following table(s) in the font have been ignored by FontForge
  Ignoring 'DSIG' digital signature table

>>> TrueType/IBM-Plex-Sans-JP/unhinted/IBMPlexSansJP-ExtraLight.ttf
0x51f0 0x51f0 uni51F0 1001

IBM / plex

The width of 凰 (U+51f0) in Sans JP looks odd. #523

Problem

Check script and output