It will handle them, but a steady diet will probably be bad for the slide. The barrel will split on the locking lugs, and it will still function and you won't know it until failure or until cleaning. Over time the slide could develop stress points too. Tony has some stories here. I think there is a newer design for the slide. Of course, you are shooting max 147 grain so that isn't a problem I suppose.
It is much, much more important to determine if the ammo headspaces on the case mouth like an auto or on the little itty bitty rim. The former, ironically, can be the biggest danger if they space too long. the latter will just blow the barrel at the locking lugs and you'll see it easily. Your witness was built for SAAMI case specs circa 1997. That means rim not mouth. You will be best off perusing boards like the CZ forum (the clone club) and glocktalk. Disregard anything about a 1911 platform aside from ammo characteristics.
If it isn't a barrel marked 9x23 don't try it. kaBoom.
If the barrel says only 38SA and not +P, get a new barrel. They used to be about $40. The polygonals are really cheap even.
Look into a 9mm barrel, just for cheap shooting.
learn to reload if you are going to shoot 38SA.
If you want the punch of a badass 38SA then load some with a 147gr bullet at reasonable velocities. A 357 sig can't touch that shit. Kind of like a 38 special with a 158gr wadcutter, a 9mm would be on the hind end.
There is a bunch more. You have the large frame, you can swap to anything nder the sun almost. Tony and I have witnesses, they aren't olympic material but they can kick the ball for a feild goal. post away.