Edit toolbox/shared/controllib/engine/+ltipack/@tfdata/dispsys.m . Save a copy of the original file because you will want to fix the code back to the original after you see what the results of your requirements look like in practice.
Look at approximately line 145 inside local function poly2str and change
to whatever format you would prefer, such as '%.4f'.
If you use a %f format, then for example
>> sprintf('%.4f', 6.645e20)
but remember then that
>> sprintf('%.4f', 6.645e-20)
I would suggest that for your purposes, the best format would be '%.324f' . If using an 'e' format is not acceptable, then %.324f is the minimum width format that permits you to reliably distinguish between all possible numeric values including eps(realmin) and 2*eps(realmin)