If you look at GitHub, you find a kind of CSS there
http://​​​​​​​https://github.com/intersystems-community/webterminal/tree/master/src/client/scss
They might be present somewhere in your installation.
​​​​​​​You may play with it at your own risk

again YES !
Any expansion is related to an extension of the internal mapping structure of the  .DAT  file
written to disk If you don't have any restrictions on disk space, you consume the related
overhead in 1 single shot at a time that you control (e.g., startup)
 

A possible escape from that trap could be to use a dedicated box
That just runs TCPTRACE
So the message runs CLIENT -> BOX -> SERVER -> BOX -> CLIENT

Of course, a qualified network manager might use Wireshark for this issue