OK - gotcha! Although the 1RM calculation is likely inaccurate, I can sure see how you can just use the number as a motivation tool and for measuring relative progress.
Are you able to do high bar squats? I noticed when I switched from low bar to high the big releif on my arms and shoulders, not too mention less leaning forward.
With that said, it is admirable you do the fronts. Nothing wrong with doing them as opposed to back squats.