Reload Columns

I am new to Sigma Grid, but so far am loving it. Currently I have it building a grid that has a locked list of Students and then it builds the rest of columns dynamically. The dynamic list are assignments and student grades. So far what I have created works fine, but I am trying to make it a little better. Currently there is a drop down list allowing the selection of a "Period" of time to see a certain set of assignments. What I have it doing is when the drop down is changed it reloads the page with a new period so a new set of assignment columns are created. This works, but I would rather have javascript handle it better. What I want to do is when that is changed is to update the assignment columns (or all columns, as the only one that will stay is the locked student column). I searched through the documentation and can not find a way to do it. I tried of course changing the LoadURL and then .reload(), but of course this doesn't work as it leaves the old columns there and doesn't add the new columns.

Unless there is a way to handle this, that I am missing I believe I have 2 options:

1. Have the div with the grid update, so that it gets created by ajax, so when the select is changed it will reload the grid with ajax somehow.
2. Have all possible assignments created and then hide/show certain assignments when the select is changed.

I haven't created the "Save" option yet. But I could see a problem with option 2 if I load all assignments and when it is saved all assignments are sent to be processed. Is that how it works or do only the changed fields get sent, and hidden fields will not cause more processing?? Option 1 works, but seems like alot of work.

I am just looking for suggestions on what everyone thinks is best or if I am missing a easier method.
Thanks,
Shawn