Apparently, it can be done natively with Yomichan, by adding a new template.
- Enable Advanced Yomichan settings,
- Configure Anki card templates…, at the bottom
- Add a new template
{{#*inline "frequency-innocent"}}
{{~#if (op ">" definition.frequencies.length 0)~}}
{{~#each definition.frequencies~}}
{{~#if (op "===" dictionary "Innocent Corpus")~}}
{{frequency}}
{{~/if~}}
</li>
{{~/each~}}
{{~/if~}}
{{/inline}}
- Configure Anki card format…, and type in
{frequency-innocent}
for where you want this data. (It doesn’t seem to appear in the dropdown.)
Actually, I have another edit for Pitch Accent.
{{#*inline "pitch-accent-list"}}
{{~#if (op ">" pitchCount 0)~}}
{{~#if (op ">" pitchCount 1)~}}<ruby lang = 'ja-JP'>ol<rp>(</rp><rt><span class='spoiler'>{~/if~</span></rt><rp>)</rp></ruby>}
{{~#each pitches~}}
{{~#each pitches~}}
{{~#if (op ">" ../../pitchCount 1)~}}<ruby lang = 'ja-JP'>li<rp>(</rp><rt><span class='spoiler'>{~/if~</span></rt><rp>)</rp></ruby>}
{{~> pitch-accent-item-disambiguation~}}
{{~> pitch-accent-item format=../../format~}}
{{~#if (op ">" ../../pitchCount 1)~}}<ruby lang = 'ja-JP'>/li<rp>(</rp><rt><span class='spoiler'>{~/if~</span></rt><rp>)</rp></ruby>}
{{~/each~}}
{{~/each~}}
{{~#if (op ">" pitchCount 1)~}}<ruby lang = 'ja-JP'>/ol<rp>(</rp><rt><span class='spoiler'>{~/if~</span></rt><rp>)</rp></ruby>}
{{~/if~}}
{{/inline}}
That is, else
clause for “No pitch accent data” is deleted.
However, I am not sure if frequency can be added to existing Kanji cards as well?