I'm getting ready to glue up my 7th bow, a Bingham style 60" recurve with a slightly shortened riser. Having settled into a repeatable profile, I can predict that this stack of materials in hand is going to come out lighter than I would like (.265 will probably get me 40 lbs).
I've got a short piece of black .050 glass on hand. If I threw this in as a power lam, would it ruin the profile/performance of the bow? Will it increase draw weight without adding more hand shock? If it's an accepable idea, how far past the fades should a power lam extend?

I could be way off here, but I think the power lam is better used in a r/d bow or hh style longbow, not so much in a recurve. But def wait for someone who knows a bit more about those. I've never used a power lam before, just read about them here.

I think of a P lam as a way to extend a super thin riser fade in an effort to move the bend further away from the actual fade out.  They do not, by themselves, add power, or performance...simply they modify a limb design.   They are very useful in short riser bows, such as on a 11 or 12" riser hill bow ....or even on a short riser recurve, such as a Herter's 46" bow (that takes about a 12" riser).  I think they are also useful in risers which are hard to get a long thin fade (i.e. phenolic).  So if you shortened your riser in the Bingham style recurve, and wanted to keep the same limb design a p lam may help get you back to where you were with the original long riser.

You could put it in there to bring the riser back to the original length. Just feather it down just like grinding your fade. Most guys glue them in on the belly ramp.

I only build one piece bows, but I have used powerlams in a few builds. In this picture I marked the end of the riser with one bullet and the end of the P-lam with the other. I made the P-Lam out of a 040 actionboo parallel and only tapered the last 2 inches of it..I think most guys run the taper the full legnth..It does add a couple of pounds to the bow for the stack thickness..  

Bullets and bows!?! Robert, it's good to see you've got a good balance between traditional and modern! Those look to be 30-something cal--the likes of which we haven't seen on store shelves for months now.
O.K., back to archery...I'm glad to hear that a p lam may get me back some weight I gave up when I shortened the riser.
BTW, do R/D designs have significantly less hand shock than recurves?