Glad that it worked out in the end. It’s a pity that different Android versions and custom ROMs have this setting in different places, I guess this is also making it impossible for the developer to put a direct link to this setting in Heliboard that would work for all users.
As other user said: Organic Maps uses data from OpenStreetMap, so the best thing is to go there and see how the roads in that town can be mapped better, if bike lanes are present, and if other characteristics of the roads that make them more/less attractive to bicycles are tagged.
I understand this can seem daunting to someone who has never used OpenStreetMap, but I’d encourage you to at least add a note on the “death trap road” to let other, more experienced, users know about the issue and check the tagging of that and other roads.