I was reading where soldiers were shooting submachine gun ammo out of the early Sigs and cracks were forming. Then they went to a Heavy frame Sig model to prevent that. Have read that SMG ammo can be pretty hot.
I believe the original ammo for P210 was PP41, 124gr bullet, 350M/sec or 1150ft/sec, 2600 bar or 37,709 psi.
9mm NATO ammo is 124 gr, 36500 psi or 2516.58641 bar, so pretty close to the PP41 ammo.
+P is about 2655bar or 38,500psi, so a smidge over PP41. A '92 P210-6 is probably fine with +P... But I personally wouldn't do a steady dose of it just because...
I've shot 9mm NATO out of my Sig P210 and thought it was fine. Very smooth. Had no problems... Well, the only problem was me not being as accurate as the pistol.