solar panels: multiple roof surfaces on one inverter string?
I actually do the same thing on my micro inverters. I have a vertical dawn facing panel on a wall connected across a normal winter zenith facing panel on the roof.

Panels have a soggy voltage-current curve. You can parallel them. If one is in darkness, the diodes prevent reverse current. (This is debated endlessly, so I checked with an ammeter to be sure no current goes into the dark panel)

The drawback is that for each level of illumination, there is a V-I maximum power point. If two panels are at different illumination (e.g 1/3, 2/3) then they can't be running at the perfect max power point (MPP), so you won't get the max possible from them.

But it doesn't really matter. The one providing most of the power will be close to MPP,

In my case I have 550W of panels connected to a 250W micro invertor. I can't use the max possible power (only 400W due to angle between panels) anyway. The point for me is to increase the time I get any power. This is about the hostile tariff regime here, and also the relatively low cost of an extra panel relative to system cost.