Ruger LCR's crane lock-up?

I recently gave away my S&W 640 to a close friend. I replaced it with an LCR. Now all double action revolvers I own are Ruger. SP101 and LCR have decidedly different systems of locking crane to frame. SP101's system appears to be significantly more robust, permitting less leverage to distort or "bend" the crane from proper alignment. LCR appears to be a less robust version of S&W's [older] two-point lock-up.

While I would not anticipate my LCR being shot "loose" from 357 Magnum defensive ammunition, a three-inch 357 LCR appears to be a competitor of S&W's three-inch Model 60/60 Pro revolvers that, I believe, are intended to function as EDC and general purpose field handguns - that is, shot substantially more than a belly gun LCR.

When I compare my four-inch SP101 with LCR, two questions come to mind:
1. Why did Ruger design the LCR with a less durable crane lock-up than any other currently manufactured Ruger double action revolver? I detect no reason for the design change.

2. If LCR has less durable lock-up than SP101, et al., what service life does Ruger expect for LCR 357 Magnum revolvers - using 357 Magnum ammunition?

I have an LCR .357 also and I don't think Ruger designed it for all day plinking with .357 Mag ammo.
Most folks shoot .38 Specials thru it for casual practice plus a cylinder or so of .357.
It fits it's niche as a good SD small revolver very well. Mine doesn't feel as substantial as my S&W Model 66.

I would like you to specifically show how the frame lockup is different than the SP, and how it would allow more eventual "distortion" in the future. If that is actually possible to predict, how does it conflict with what Mus408 wrote? Finally, how about a cost/benefit analysis?

I'll do my best to respond to your replies.

I have no access to creating or loading graphics to web pages. Dinosaur PowerMac G5 and OSX 10.4.11 were superceded in 2005.

Cost/benefit analysis? I do not understand this phrase - unless you mean is one revolver more expensive than the other. My replacement cost was almost exactly the replacement cost of a 640-1. Since my LCR was [barely] used, and any 640-1 must be used, that comparison is accurate. FYI: 640-1s are perceived to be more valuable than many later versions. No lock. No MIM parts. The MIM doesn't mean much to me. No lock does.

Visualize the three points of crane lock for the S&W New Century first model: rear of cylinder [pin] to recoil shield of frame; into underlug of barrel where barrel threads into frame; and into a spring-loaded pin at front of underlug. SP101's crane lock-up is similar to the first two Triple Lock lock points - not identical, though. LCR deletes the second lock while maintaining numbers one and three - again, not identical, though. Distance between LCR's front and rear points of lock-up, being longer than were number two included and number three deleted, has more room for flex and tolerance. Flex and tolerance appears to exacerbate increase of unintended crane movement and wear of/around cylinder pin's lock-up - numbers one and three for LCR

SP101's number two lock point is, perhaps, more durable than Triple Lock's equivalent by the nature/design of its fastening. I cannot report this with certainty, though.
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I compared LCR with S&W Model 60 series ("J" frame), not with Model 66 ("K" frame). So you may be accurate regarding perceived substance.
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We agree on LCR's utility as EDC/SD revolver. Gee, I bought one to replace my S&W 640-1 at about its price. I use Remington 38 Special +P 158-grain LSWC-HP. Were I to own a Model 60 three-inch rather than my SP101 four-inch, I would be inclined to shoot 357 Magnum a substantial part of its use, as I am with my SP101.