+1 on nickobec comment
I have 2 pairs of these G8 knockoffs, have mine cut to 42 (26cm) but it's pretty much the limit. You can even cut more, but then I believe the arch will be too much ahead even on the limit of positioning
either way, I think it's worth for the price, at least to try.
Both my pairs have 3yrs of use and are still going, the only issue I had is that the arches soften with time (like >1yr of use), but then I just get the upper number and keep on using it. Seems even the original one experience this and you need to get replacements after some years...