Just tracking back a few years. In the 2000 - 2005 time frame, if we come across such cracks on toe, we would take it to a sports shop and they would tie a gut around the crack.
Well, let me explain it a bit better : The Badminton racket gut will be usually tied around the crack, using the gutting machine for strength and tightness. Prior to that, they do apply some glue and so dome sanding around the crack as well. Once the Gut is tied in properly, for this size of a crack, the gut width tied would be about 1cm. Which will cover the length of the crack. A old SG of mine had a similar crack and had it gutted, which lasted for another season without any problems from that toe area.
Well, it was in India where this was done. Of late with face protectors and fibre glass tapes around, not sure, if such practice still exists.