I call hogwash, when I was LDS it was 10% of GROSS not net income and tithing settlements were not optional, well not if you wanted a temple recommend. And this was several wards and stakes, not just one bishop.
Sounds like you don’t follow your own religion very well, Logo.
For your guidance in this matter, please be advised that we have uniformly replied that the simplest statement we know of is that statement of the Lord himself that the members of the Church should pay one-tenth of all their interest annually, which is understood to mean income. No one is justified in making any other statement than this. We feel that every member of the Church should be entitled to make his own decision as to what he thinks he owes the Lord, and to make payment accordingly. (Quoted by Vicor L. Brown, Ensign, April 1974)
So far as I know, this is still the official word on tithing.
Note that no one, not even a bishop, is authorized to go beyond what the First Presidency has written. How members calculate their tithing is between them and the Lord; the bishop has no say in the matter.
As for the temple recommend interview, the question is whether one is a full tithe payer, not whether one attended tithing settlement. And every member is entitled to decide what it means to be a full tithe payer.
(You may be right that I do not follow my religion very well. Fortunately, God is both just and merciful; and by His grace I may be perfect in Christ. )