Loop text that wipes left to right using FFMPEG drawtext filter
This works:
-vf "drawtext=text=string1 string2 string3 string4 string5 string6 string7 :expansion=normal:fontfile=foo.ttf: y=h-line_h-10:x=(mod(5*n\,w+tw)-tw): fontcolor=white: fontsize=40: shadowx=2: shadowy=2"
See Desmos for how it works.
x-axis is the video width.
y-axis is time.
The black line is the width of the image (adjustable in Desmos through a slider, x).
The black shade is the text in my formula.
t in Desmos corresponds to tw in FFmpeg CMD, which is the width of the text.
Blue area is the text in your original formula.