Like in most Sales cycles, certain key account information comes in only during the latter stage of the deal. Some of these attributes are associated with an Account, not a Deal. 

How do I get Zoho to mandate filling up this information at an Account level when the Deal stage changes from say x to y?

I know it's possible to set this up within a deal itself whereby certain fields within the deal can be made conditionally mandatory depending on the stage, but this doesn't solve my problem.

I can't enforce this behavior at the Lead stage either as it's too early in the Sales process to get the information I am referring to above.

Are there any workarounds for this if not directly possible?