I’ve long had a gut feeling that the courts would uphold training requirements as constitutional, but that once this would happen, training would quickly become the means by which hostile jurisdictions attempted to prevent people from exercising their Second Amendment rights.
This has been happening in Wisconsin, with the Department of Justice making unlawful training requirements not sanctioned by law. Wisconsin Carry is filing suit over this these practices, specifically over class size mandates.
In other civil rights struggles, the Courts have often tried to be conservative in their ruling, and later realized they had made a mistake. “Separate but equal,” probably being the most famous court-invented fallacy to attempt to avoid doing the right thing. Hopefully, like other civil rights struggles, once it becomes apparent to the courts the states can’t play with their ruling toy nicely, they’ll take the toy away from them entirely. That will depend, over the long term, how committed the courts are to protecting the right seriously.