The price of liberty is eternal vigilance
Of legislature, executive (ie administration) and judging; and where each do cross and mingle: my example is minor compared to what you describe, but important if you are an individual affected. As far as I know my example - of spontaneous judicial guidance - applies mostly in family cases. Twice I've written up recently cases (eg https://www.iclr.co.uk/blog/commentary/freezing-orders-duty-of-candour-and-without-notice-applications/) where High Court judges have in effect strayed into legislating by issuing guidance on what they think the courts should do. This is not a question of judges developing the common law by their decsion in the case: that is what judges are for. This is judges telling us what they think the rules should be. In both instances I am thinking of judges have given 'guidance' but have read underlying cases wrongly - even untruthfully. That is, judges are telling all of us what we should do (politics), but getting the underlying law fundamentally wrong.
A second example (to that mentioned above) is from the end of March: Ms/Miss/Mrs Justice Lieven issued guidance in trying to contain the extent to which abused women can apply to court for protection. The judge failed properly to read the case law on which her 'guidance' was based. How many abused parties (mostly women and children) will suffer as a result? If law is to be changed, or regulations amended or - as you say - court information issued on-line, with varying degrees of effort alteration can be done.Once a High Court judge has spoken and judgment has been handed down, can that be changed. Now there is a question...
"I raised this with the Supreme Court which, to its credit, rapidly corrected its website"
There is legal commentary; there is good legal commentary; and then there is pointing out the law to the Supreme Court.
The practice of 'ticketing' Circuit Judges to try discrete categories of crime is enveloped in mystery. Due process would suggest that it might be preceded by an 'expression of interest', followed by such further training as the topic objectively warranted. I cannot say whether this is the practice in 2023; but it certainly was not when I first became a ticketed judge in the 20th century.