Using Unused Sectors

I am trying to estimate the impacts of an agricultural crop that can be grown in different ways depending on place and growing technique. We have constructed the production function and the components of value added. We also have employment and the value of output. I saw a post where DougO advises one to use unused sectors to build a new sector. I would like to build a new sector for each possible production process. Can one do this or should we simply overwrite the values for the generic agricultural sector that contains the crop? Other suggestions? If one adds a new sector my understanding is that one selects an unused sector and the one modifies the employment/output/employee compensation to change the value added and absorption coefficient in the customize>study area data. Then, one modifies the production function which one can save and then export. Lastly, one reconstructs the industry accounts and the multipliers. Is this how it is done? I find that when one enters the production function it will often error out - even when the sum of the sector absorption coefficients equals the overall coefficient. What is the best way to avoid this problem? The model has also crashed and become unusable when trying to save the production function. I note that the SAM matrix for the added sector changes depending on which unused sector is used. What should be done to mimic the SAM of the generic agricultural sector that we are modeling? Thanks.