Characteristic of Sati?

Suttas say: Recalling Past actions

Modern movements say: Mindfulness, awareness, attention, manasikara

Abhidhamma reserves it only for kusala cittas while Sarvastivada says it is common to any citta.

Some say: Sati = Appamada (;and some say it isn’t)

The above is from a video-lesson and the below is from a forum.

The following abstract is just to give some context and not a solution.

Abstract - A Study on the Memory by using ‘Smruti, Smara’ and ‘Sati’ in Sanskrit and Pāli Literature.

In the division of ancient Hindu or Vedic literature consists of two scriptures viz.
śruti and Smrutiscriptures. Literally, śruti means that ‘what is heard’ and śmruti
means that, ‘what is remembered’. Although, these definitions are regarded as
Hindus literature, of these two terms Smrutihas been occurred with reference to the
Memory of individuals not only in Vedic literature but also in Buddhist Sanskrit
literature. Smara is another term for using to clarify the Memory of individuals in
Vedic literature.On the other hand, Pāli term Sati is performed in contradictory
state in combining with the concept of Memory. Many distinguished scholars have
speculated that Sati is derived from the Sanskrit term Smruti. Furthermore, Collect
cox discusses that, the term Sati of Early Buddhism has been affected to the
Sarvāstivāda Abhidhamma as Smruti.Further, Ghānaponikathera points out that,
Dhammasangani definition of Sati has been limited for defining only in good
consciousness (Sobanacitta). It is very interesting to note that, all these usages are
important with the concept of Memory in both Hindu literature and Buddhist
literature (Pāli and Sanskrit).Therefore, this research is aimed to discuss about the
terms of Smruti, Smaraand Sati in order to clarify the Memory of individuals.

How should we understand the Individual Characteristic of Sati?