Q.What Could Cause New Leaves On Calamondin Tree To Be Very Large?
43 year old calamondin tree has begun growing leaves up to 5 inches long on the same branch as older 1.5 to 2 inch leaves. It almost died last year, but with pruning, debugging and repotting it pulled through. It has never had leaves this large; I’m puzzled.

Certified GKH Gardening Expert
This is quite normal for a citrus that was struggling, and when it is corrected the tree will resume with proper growth.
These are the leaves that you want to see. It indicates that the tree is healthy.
It is going to look strange for awhile, but restorative pruning can help once it starts growing, vigorously, again.
Here are some articles that will help:
https://www.gardeningknowhow.com/edible/fruits/oranges/orange-tree-container-care.htm
https://www.gardeningknowhow.com/edible/fruits/citrus/growing-citrus-trees-indoors.htm
https://www.gardeningknowhow.com/edible/fruits/calamondins/growing-calamondin-trees.htm