Hi Ricardo
It was me who did the bend test. Here's my two cents:
First, that looks like a pretty nice piece, lots of character! A lot of my wood looks like that too.
Sapwood is probably fine in a bow, even though heartwood is probably better, unless you tend to make a lot of hinges and set during tillering.
That said, my experience is that it is much easier to chase a ring on the heartwood. I've never tried Osage, but from video it seems comparable, though the earlywood is not quite as "crunchy" as in Osage. As others have said on this forum, the sapwood has a sort of rubbery texture, and with those knots, I at least would need all the help i can get.
The sapwood gets mouldy much easier than the heartwood, so keep the bark on, and keep it dry, with lots of air circulation. It also likes to check at exposed ends, so keeping the bark on is your best bet, unless you reduce it to near-bow dimension right away.
Last, my experience is that it is much, MUCH easier to chase a ring, at least on the heartwood, once the wood is dry, so wait with that untill you are ready to start the bow.