Number stringification needs to produce uppercase E
we have a mismatch somewhere between 'E' and lowercase 'e'
for the scientific format.
'=5E-324' is displayed as result '5E-324' in the cell,
but in formula bar or cell edit '=5e-324'.
Actually not very important, but in consequence 'exact' fails
between a cell with text "5E-324" and another with 'value'
5E-324. And switches to TRUE if you change the text to "5e-324".
Besides that input (5e-324)
is displayed as $ (0.00)
cell format changed to accounting and 'formula' changed to
-5E-324
, but that may be a feature I haven't learned yet.