Freeze selection

I was able to speed up the freezing issue after freezing a large number of cells by defining two selections -- freeze and unfreeze -- and saving those to code_array's cell_attributes (instead of each cell as an individual selection).  

However, it still stutters a little bit after freezing a huge selection and I'm not really sure where else to look.  Any ideas?

I would also like to speed up the actual freezing mechanism if you have any ideas for that.  Freezing the entire default sheet full of nothing takes a strangely long time...