My Inverter's Capabilities...confused?

[cattus]

@plonkster

When the Multi is grid-connected (with ESS installed), the output of the Multi is literally connected to the input, and the inverter feeds additional energy (up to 900W for your 1200VA rated unit, because grid-connected is limited to 80% of total capacity) into this combined connection.

Two Questions regarding this:

1. I’ve looked for this 80% in the documentation, but have not found it. Could you direct me, if you know where?
2. I watched a video of someone testing the grid power quality with an oscilloscope, in the USofA, seems their grid power is quite “dirty”. Once a Pure Sine Wave Inverter was attached between the grid and oscilloscope (thus, ultimately, one’s appliances) a lovely clean wave of current showed, so if the “…output of the Multi is literally connected to the input…” would this ‘cleaning up’ still be in effect or is it now negated?

@Phil.g00

Your inverter can relieve your draw from the grid by up to 1200W.

So given these two quotes by @Phil.g00 and @plonkster above is the correct way of thinking about this Multi with ESS like zo:
If the grid is a donkey and your load is a cart your inverter (&battery&PV) is a man standing behind the cart giving a little shove?

(I have questions about the ESS in general so may start a new thread…)