Can't get anti-aliasing text to work

Hi all,

I’ve bought a reTerminal E1001 recently, and was thrilled to get it up-and-running with esphome. Works great so far! However, I’m having trouble getting the anti-aliasing for text to work.

So, the display has 4 levels as far as I know, (black, grey, another grey, white), so this should theoretically be possible. I used esphome designer as a starting point and made some changes to it. Anyway, the most important thing concerning anti-aliasing are these, I think:

font:
  - file:
      type: gfonts
      family: Roboto
      weight: 700
    id: font_roboto_700_32
    size: 32
    bpp: 4

[....]

display:
  - platform: waveshare_epaper
    id: epaper_display
    cs_pin: GPIO10
    dc_pin: GPIO11
    reset_pin:
      number: GPIO12
      inverted: false
    busy_pin:
      number: GPIO13
      inverted: true
    rotation: 0
    model: "7.50inv2p"
    update_interval: never
    full_update_every: 30

    lambda: |-
      const auto COLOR_WHITE = Color(0, 0, 0); // Inverted for e-ink
      const auto COLOR_BLACK = Color(255, 255, 255); // Inverted for e-ink
      const auto COLOR_RED = Color(255, 0, 0);
      const auto COLOR_GREEN = Color(0, 255, 0);
      const auto COLOR_BLUE = Color(0, 0, 255);
      const auto COLOR_YELLOW = Color(255, 255, 0);
      const auto COLOR_ORANGE = Color(255, 165, 0);
      auto color_off = COLOR_WHITE;
      auto color_on = COLOR_BLACK;

[....]

          it.printf(400, 10, id(font_roboto_700_32), COLOR_BLACK, COLOR_WHITE, TextAlign::TOP_CENTER, "%s %d %s", id(todays_day_name_w_mkpxur3u2jk73).state.c_str(), time.day_of_month, id(todays_date_month_year_w_mkpxur3u2jk73).state.c_str());

So, as far as I can tell, the display model used is not just black-and-white. The fonts are rendered with 4 bits-per-pixel and the printf have a background color. Anything that I’m missing?