I don't find Fraktur (Tannenberg Fett in this case) that difficult to read, at least when using a big character size like this one. I too think that it's not extremely appropriate for the romaji in the Japanese section and I tried to find a more suitable font, but to no avail. Every other one looked (as) strange beside the Japanese characters. So I decided to use only the two fonts you see here.
Very true. That’s a strong objection. I was aware of the Antiqua–Fraktur dispute en.wikipedia.org/wiki/Antiqua%… For that reason I refrained from using a random Fraktur font. Until I found the Tannenberg font de.wikipedia.org/wiki/Tannenbe… which was widely used in Nazi propaganda (it even has two Algiz runes). It was created in the 30s when Fraktur was the preferred Nationalsocialist typeface. The later preference for Antiqua, probably largely based on the practicality of that script for foreign propaganda, reminds me of a similar Japanese policy. The use of the Kana syllabaries was preferred over Kanji for the teaching and spreading of a simplified Japanese in occupied territories, even in Manchuria. There were also proposals for the total elimination of Chinese characters. In the contex of Japanese nationalism before and during WWII there was even an interest for Jindai-Moji eos.kokugakuin.ac.jp/modules/x… allegedly purely Japanese symbols from before the introduction of Chinese characters.