Yes and no. The fact there is more metal to stretch does add resistance to lateral plastic flow (diameter expansion). However, unlike large rifle primers, which seem to be pretty uniformly stamped from 0.027" brass sheet,
small rifle primers come in a range of cup wall thicknesses, so you have the problem that some can blow out and pit your bolt face more easily than a large primer is likely to do.
If you do as board member F. Guffey does, and measure your chambers by transfer measurement and resize based on not moving the shoulder back too far from the length of your actual chamber headspace, you will have less impact expansion of the head to begin with. You will still have pressure-caused flow, but avoiding the initial slam helps. (Mr. Guffey invented a nice tool that measures flash hole expansion as the earliest sign of a case head starting to get too wide, and he was kind enough to send me one. Unfortunately, I don't think he has it in current production.) The problem, in part, is that every maker seems to use slightly different alloys and levels of work hardening at the head. Because they sometimes outsource brass forming among one another (see the current Norma manual for how unexpectedly frequent this is; Norma has made Federal and RWS and Remington cases at times), you also can't just rely on a certain brand to be a certain way always. You have to check each lot. When you do, you'll find some lots handle pressure better than others, while still others let you get more reloads before they start to split. There always seem to be trade-offs.
There is a second, less commonly referenced consideration: Small primers contribute less to the total start pressure. This means primer-to-primer variation is lower when you use a small base primer, and still lower when you have the smaller European small primer flash holes. if the powder you use fills the case well, so there isn't significant extra space in need of primer pressurization, and if the powder ignites easily, like a single-base stick powder, then there is potential for improved velocity and pressure curve consistency. I remember about 15 or 20 years ago RWS produced and unusually mild lot of small rifle primers and the benchrest community went into panic buying mode over them, trying to get all they could. They found it helped produce smaller groups in their circumstances. One could argue about why, but I just wanted to throw it out there so it can be viewed as one more variable to experiment with in brass that has both primer pocket sizes available.
