Classifying a CHARTS OF ACCOUNT for taxes
In our country if you sale something to a local customer you need to add 15% to the sales cost and charge that tax called GST form the buyer.

When you spend money if you paid to a local seller he will also charge you GST.

You then need to balance your GST expenses vs. your
GST income and that would be your GST Debt or Return to the taxation authority.

The strongest accounting software here is xero, because at the level of Chart of Account, you can determine one time if and expense or a revenue are GST related (yes or no).

Like this you would sit with your accountant once, explain the nature of your revenues and expenses and you will click the GST related on the correct revenues and expenses at Chart Of Account.
You will do this action once.

From what I understood form Zoho support that is not the case with Zoho Books.

I understood that with Zoho books you will need to manually do this for each transaction that you classify again and again...

This is very bad, and my suggesting is to enable one time classification at Chart of accounts.

Other ways, using Zoho Books is pointless (at list for me and I also believe for other customers in our country)