It took more than a year, but Nijisanji EN seems to finally be past the absolute worst of it. With very few exceptions (basically just 2 non-graduated ones), all EN channels are either growing or stagnant. Granted, the growth isn't earth shattering, but not seeing red numbers across the board is already a massive improvement.
Keep in mind that the developer of that website is a lazy fuck, so Denauth and By The Beat are not in this chart.
Last 30 days for the rest:
Twisty -
900
Ryoma -
2000
Klara -
1800
By The Beat -
100k+