In Languages>Latin>IPA, it would be good to include ascript (U+0251), ascriptturned (U+0252), tonebarhighmod (U+02E6), and a couple others. Is this forum a good place for reporting such missing glyphs?
Yes, the tone bars ˩ ˨ ˧ ˦ ˥ (02E9 02E8 02E7 02E6 02E5) should be in the IPA group.
The ⱱ (2C71) should also be added, it was adopted as a new IPA symbol in 2005. See https://www.internationalphoneticassociation.org/content/full-ipa-chart
Many modifier letters or diacritics (and letters with middle tilde) should be in the IPA group as well since they are in the 2005 IPA chart.
tones (alternates to tone bars): low U+0300, high U+0301, falling U+0302, mid U+0304, extra-high U+030B, rising U+030C, extra-low U+030F, high rising U+1DC4, low rising U+1DC5, rising falling U+1DC8 — and Unicode also has low falling U+1DC6, high falling U+1DC7, falling rising U+1DC9
nasalization U+0303
centralized U+0308
short U+0306
advanced tongue root U+0318
retracted tongue root U+0319
no audible release U+031A — alternatively ˺ U+02FA is sometimes used since many fonts have poorly designed U+031A
less rounded U+031C
raised U+031D
lowered U+031E
advanced U+031F
retracted U+0320
breathy voiced U+0324
voiceless U+0325 (also U+030A when above)
syllabic U+0329
dental U+032A
voiced U+032C
creaky voiced U+0330
velarization or pharyngealization U+0334
more rounded U+0339
apical U+033A
laminal U+033B
linguolabial U+033C
mid-centralized U+033D
Since U+0334 is a combining overlay diacritic the following were added to Unicode as well: ᵬ ᵭ ᵮ ᵯ ᵰ ᵱ ᵲ ᵳ ᵴ ᵵ ᵶ (1D6C 1D6D 1D6E 1D6F 1D70 1D71 1D72 1D73 1D74 1D75 1D76)
The deprecated ʤ dezh and ʧ tesh are in your IPA group, that’s fine since they are still common. You probably want other deprecated symbols ʣ ʥ ʦ ʨ ƥ ƭ ƈ ƙ ʠ that are as common or those that are more rare (like U+1D70…U+1D9A). One might want non standard symbols (like ɿ ʅ ᴀ) that are quite common in some contexts.