Surface Reflectance Basemap Quad download via API

Hello Planet-Community,I want to try Planet surface reflectance basemaps (https://developers.planet.com/docs/data/sr-basemaps/) to evaluate if it is suitable for my research project before purchasing wider access. In particular, I want to download a GeoTiff quad tile of a quarterly basemap mosaic via Python, as I have already implemented a processing tool chain which works for another satellite image provider. However, despite quite some effort, I could not yet fetch a single Planet basemap quad and are struggling with a bunch of problems:1) How to access surface reflectance basemaps (BGRN) via the browser on https://www.planet.com/basemaps or through the QGIS plugin? I followed the instructions given at https://developers.planet.com/docs/integrations/qgis/discover-basemaps/, but can view only visual (RGB) basemaps.2) How to get an overview of recent quarterly basemaps at zoom level 16? I queried the basemap overview as described in https://developers.planet.com/docs/basemaps/ with curl https://api.planet.com/basemaps/v1/mosaics?api_key=MY_API_KEY,but only monthly mosaics up to zoom level 15 until March 2020 are displayed. The latest basemap offered by the cli tool pbasemap is from March 2021.3) How can quads be download through the browser? I followed the instructions given at https://assets.planet.com/marketing/PDF/Planet_Basemaps_User_Guide.pdf to download tiles from https://www.planet.com/basemaps/#/mosaic/global_quarterly_2022q2_mosaic to select a tile with the "Draw area" tool but there is no download button.4) How can quads be downloaded via the API? The instruction given under "Send Request and Check Status Code given" at https://developers.planet.com/docs/planetschool/downloading-quads-from-a-mosaic-using-basemaps-api/ result only into the 401 (Unauthorized) error. Trying the same via the Order-API (https://developers.planet.com/apis/orders/basemaps/) results in the message “our org is not permitted to order the following quads”. The cli tool pbasemap also says I do not have permissions. It seems as if quads cannot be downloaded with an account status of "Basic User". Any help will be appreciated