Regarding Dhp 30, There are so many and diverse translations given for pamāda/appamāda. Heedlessness/heedfulness. Negligence/earnestness. Negligence/diligence. Carelessness/carefulness. Unawareness/awareness.
Here is the commentary (as translated by Carter & Palihawadana with their unconventional translation of the key terms. appamāda= “awareness” sati= “mindfulness”). I grabbed the pali commentary from Tipitaka Pali Reader, Dhammapadaaṭṭhakathā.
tattha appamādoti padaṃ mahantaṃ atthaṃ dīpeti, mahantaṃ atthaṃ gahetvā tiṭṭhati. sakalampi hi tepiṭakaṃ buddhavacanaṃ āharitvā kathiyamānaṃ appamādapadameva otarati. tena vuttaṃ – "seyyathāpi, bhikkhave, yāni kānici jaṅgalānaṃ pāṇānaṃ padajātāni, sabbāni tāni hatthipade samodhānaṃ gacchanti, hatthipadaṃ tesaṃ aggamakkhāyati yadidaṃ mahantattena. evameva kho, bhikkhave, ye keci kusalā dhammā, sabbete appamādamūlakā appamādasamosaraṇā, appamādo tesaṃ dhammānaṃ aggamakkhāyatī"ti (saṃ. ni. 5.140). so panesa atthato satiyā avippavāso nāma. niccaṃ upaṭṭhitāya satiyā cetaṃ nāmaṃ.
“Awareness” illumines a massive meaning, spans a massive content; for the entire Word of the Buddha included in the three piṭakas taken up and given articulation, boils down to the word “awareness” only. Therefore has it been said: “It is, O Monks, like the case of the many kinds of footsteps of moving creatures—all of them gain inclusion in the elephant’s footstep: by its massiveness, the elephant’s step occupies the foremost place among them. In the same way, O Monks, whatever wholesome mental states there are, they are all awareness-based, they all converge in awareness; awareness occupies the foremost place among these mental states.”
Now this [awareness] is in essence “not being bereft of mindfulness”; it is [just another] name for constantly occurring mindfulness.
pamādoti pamajjanabhāvo, muṭṭhassatisaṅkhātassa satiyā vosaggassetaṃ nāmaṃ.
Unawareness pamādo: The state of being unaware. This is a term for the abandonment of mindfulness, which is the same as the state of having neglected mindfulness.
After considering the commentary, I personally like negligence/diligence. Meaning, not neglecting the Buddha’s instruction about right mindfulness.