In time we will hopefully get some guidance as to what constitutes an external power adjuster but at the moment it seems that any power adjustment without removing the stock can be done, a number of rifles immediately spring to mind:
1) Walther LG300 in an Alutec stock, Months ago I sealed the adjuster holes on my Alutecs for this reason, the stock must now be removed to make any power adjustments.
2) Steyr LG100 & 110's fitted with External adjusters, these can take the form of the official Steyr adjuster or modification being to allow access to the standard adjuster. Steyr were aware of the potential for the external adjusters being used to turn the rifle up which is why they now produce a restricted transfer port which limits the power, the problem is this often affects the shot count of the rifles.
3) Daystate Mk3 & Mk4's that may exceed the limit if reset to factory default as turning up & down via the trigger can be done whilst in a stock.