Well then, I guess the E-M10ii built-in flash is only good for fill flash outdoors on sunny days, which is what I'd use it for. If I need flash for my main light source, I'll use a clip-on external flash.
You may go 2 ways:
1) (most efficient) a tiny compact model with tilt possibility:
-Oly FL-300R , 97g, GN 28 (smallest, but very expensive like other Oly made models)
-Meike MK-320, 150 g, GN 32 (much cheaper, I bought mine second hand)
2) use a small tilted mirror at the front of the built-in flash.
You may use hot-shoe as a mount for such improvised device - there are small diffusers for built-in flashes mounted similar way. You may cannibalise the general idea. Here's an example with hot-shoe mounting frame exposed at one of the images:
https://www.benel.eu/webshop/strobist/strobist/pop-up-flash-diffuser.html
Regards,
-J.
EDIT: From Your other thread I can see they claim Oly FL-LM3 does work with EM10 II, which solves most of Your problems, I guess. They are probably reasonably priced on after market