CDR, velocities do drop off significantly in .45 ACP as the barrel gets shorter. This creates a critical "velocity floor" for expansion. "Old school" conventional copper jacketed hollow points that will mushroom reliably out of a 5" are likely to deform much less from a 4 1/4" barrel, and perhaps expand not at all out of a 3" or 3.5".
With the shorter barrel, you have two options. One is +P velocity; a 185 grain +P JHP that does 1140 foot-seconds out of a 5" will do about 1070 out of a 3.5", which is still ahead of a standard velocity 185 grain JHP out of a 5". However, recoil with the +P is palpably snappier, especially in the smaller guns.
The other alternative is to go to a high-tech modern hollow point designed to open when fired from shorter barrels: Speer Gold Dot Short Barrel, or Winchester Ranger-T, for example.
Because they have so much shorter a slide cycle, the 3" and 3.5" 1911 .45s are indeed more finicky than their longer counterparts, as a rule.