Does anyone know where in the commentaries it is stated that dhammas exist "from their own side" (sarupato)?

[RobertK]

Another great explanation is given by Mahanama - see the translation here by Ven. Dhammanando:

Paṭisambhidāmagga

Welcome to the forum Ceisiwr. I quote something that ven. Dhammanando wrote many years ago: He translates Mahanama who is commenting on a phrase in the Patisambhidamagga : MAHANAMA ON “MATERIALITY IS EMPTY WITH REGARD TO INDIVIDUAL ESSENCE” (from the Saddhammappakaasinii, Su––akathaa-va.n.nanaa) Tattha ‘jaata.m ruupan’ ti paccuppanna.m ruupa.m. Here [i.e. in the passage he is commenting on] ‘born [or ‘arisen’] materiality’ is the materiality [existing in] the present. [elsewhere he expl…

Sabhaavena su––an’ ti ettha saya.m bhaavo sabhaavo, sayameva uppaado’ ti attho.

‘Empty regarding individual essence’: here individual essence is ‘essence by itself’; arising just of itself is the meaning.

sayam eva uppādo