There are a number of things you can do that do not require an action. These include:
You can end concentration at any time (no action required).
The performance ends early if you are incapacitated or silenced or if you voluntarily end it (no action required).
If the sword is on your person, you can call on its luck (no action required)
They obey any verbal commands that you issue to them (no action required by you).
Does this mean these "non-actions" can be performed at any time, even during someone else's turn or in the middle of dice roll resolution, etc?
(This question is a spin off of the question about when you can end concentration, answers tend to rely on a twitter post from Jeremy Crawford that just quotes the rules right back at the asker, which is interpreted by some to mean "yes, you can end concentration during other turns". This presents an immediate problem because Alter Self, for example, says "At any time for the duration of the spell, you can use your action to change your appearance in this way again." V2Blast then asserted that the key wording wasn't "any time" it was "no action", and that anything that didn't require an action can be activated when you cannot take actions. Can this argument be generalized or is it a very special case interpretation of one particular mechanic to attempt to make it make sense?)
Note: This answer is not only about Concentration. In other threads people have argued that since Concentration says "at any time" you can do it in other turns. However the other examples don't use this language. Particularly Conjure Animals specifically says "verbal command" which would normally be possible only on your turn, and does not say "at any time". Please address more than just Concentration in your answer.