For plurisubharmonic functions \(\varphi \) and \(\psi \) lying in the Cegrell class of \(\mathbb {B}^n\) and \(\mathbb {B}^m\) respectively such that the Lelong number of \(\varphi \) at the origin vanishes, we show that the mass of the origin with respect to the measure \((dd^c\max \{\varphi (z), \psi (Az)\})^n\) on \(\mathbb {C}^n\) is zero for \(A\in \text{ Hom }(\mathbb {C}^n,\mathbb {C}^m)=\mathbb {C}^{nm}\) outside a pluripolar set. We establish a new approach and introduce a new concept coined the log truncated threshold of \(\varphi \) at 0 which reflects a singular property of \(\varphi \) via a log function near the origin (denoted by \(lt(\varphi ,0)\) ), and derive an optimal estimate of the residual Monge–Ampère mass of \(\varphi \) at 0 in terms of its higher order Lelong numbers \(\nu _j(\varphi )\) at 0 for \(1\le j\le n-1\) , in the case that \(lt(\varphi ,0)<\infty \) . These results unify and imply the well-known results about Guedj–Rashkovskii’s zero mass conjecture.