I had read that mamey seedlings may take 7-10 years to flower, and I guess I assumed canistelwas similar, but I am at least finding some reports of canistel taking 3-4years in ideal conditions so maybe this is not such a shock, but it was a nice surprise to me.
It has been in rootmaker pots most of this time yet, though I'm not sure if that makes a meaningful difference it could certainly help. The roots are fully contained within the container, not reaching through into the soil if that is what you are asking.
Inga pods are the size of peapods now, I'm really looking forward to trying them... and I am having a hard time imagining them reaching the 3ft+ length that is expected for a mature tree! Hopefully they hold to maturity.