The device looks good for the price, but as far as the specs are concerned, I don't know why I would buy it.
AN870 (or ZT-255) are more precise multimeters with more amp range for less money.
The scope with 5 MSps and 30mV/Div minimum?
Even the pathetic DSO-TC2 has a 10mV/Div range and can just about display a 3mVpp signal (picture).
Is this more for electricians?
The Owon has a slightly larger display and fewer vertical divisions.
The DSO is 8 divisions and 2.4" The Owon is 5.5 divisions and 2.8".
I don't know how much your 3mV signal would be visible on it or whether the automatic measurement would be able to measure it.
Without tests, we do not know how accurate and sensitive the measurement is.
How many MHz signals do you want to measure with those test leads?
Your DSO has a BNC connector, this one only has a plain DMM measuring lead.
Based on the pictures, this one has a better display and has a few good features that are not found in multimeters of a similar price category.
If it had been released earlier, I would have bought this instead of Fnirsi and Zoyi.
The Zoyi is good despite its faults, but for a few quick measurements this Owon would be more suitable.
Unfortunately, the description is a bit incomplete.
I searched a bit and found that this is the best among Multiscopes of a similar category, with NON-BNC connectors. I found 2.5MSa/s, 300mV-200V/Div and 500mV-?V/Div. the display of those looks bad, I don't think it makes sense to compare it with the cheapest oscilloscopes, it would have been unnecessary to make this one along with the other HDS.