Here are some userscripts that can be used to modify the behavior of websites. You will need an extension that loads userscripts to install these scripts. I recommend the extension ViolentMonkey (Chrome/Firefox)
CS1XD3 Better Editor v0.4
makes the editor better probably. originally written as a devtools patchCS1XD3 Dark Theme v1.2
introduces a dark modeCS1XD3 Freeze Patch v1.2
prevents freezing of the websiteCS1XD3 Editor VIM Mode v0.2
adds vim mode to the editorAvenue Auto Login v1.0
Automatically logs in when visiting Avenue to save timeAvenue Inactivity Disabler v1.0
Disables inactivity signoutAvenue Title Changer v1.0
Changes titles such as "(4) The Relational ..." to "4 - The Relational ..."CalcCheck Sanity Tracker v1.0
Totals the minutes, hours, days, weeks, or months spent trying to debug issues in CalcChck.CalcCheck Dark Theme v1.6
Adds a dark theme and other style improvements to CalcCheckMosaic Auto Login v1.5
Automatically logs in when visiting Mosaic to save timeCS1XD3 Freeze Patch
v1.2 prevents freezing of the websiteNo instructions provided.