I had a fear of that happening myself; namely, that the metallic spray inside the case might be adversely affected by the H202 during deyellowing. But in my case, the reason I ultimately went with the gel form of LumpyBright is because H202 is expensive over here in Japan. This thread is a successor to the thread you mention in your post, and describes my own experiences with the gel version.
Of course, that thread is not going to help you now, as you've already dunked your case and have experienced problems. In my case, I did the deyellowing on a rather cool day, but a day on which I had direct sunlight all day long (no shadows from buildings, no clouds at all). I therefore had an abundance of UV light at my disposal, which clearly sped the deyellowing process along for me.
I did "dunk" my mouse plastics and some keyboard keys, since I didn't need so much of the liquid to do that. However, none of those pieces contained any metal, unlike the inside of a company Mac housing. And before I applied the gel form of Retro/LumpyBright to my SE/30's housing (on the outside only, not the metallic spay on the inside), I was careful to remove the Apple logo on front as that is paint on metal. And because the H202 I used was the normal drug store 3% (i.e., weak) stuff, I did not experience any degradation of the keyboard key silkscreened text or the text silked on the front of the SE/30 housing.
Whether you have destroyed your case or not is something we will have to determine after seeing your photos. But it is clear that you should stop the deyellow process right now to avert further damage to the shielding on the inside. I suppose that some people may contend that you really don't need to worry about the shielding even if it peels off. And that is true. The FCC won't track you down for spraying RF interference in your own home. But if you are like me, you may be bothered by the knowledge that you destroyed even an unseen part of your Mac, in which case you should revert to the gel deyellowing method instead of the liquid form.
To everyone reading this, if you have any bit of metal on something you wish to deyellow, consider well what kind of metal it is because it will be impacted negatively by the deyellowing process. In such cases, the gel form of RetroBright is your only realistic option. I know first-hand it is more troublesome that the liquid version, as you have to reapply it once an hour throughout the day. But it will give you the best results without damaging your metallic parts. Reserve the liquid form only for 100% plastic pieces, with no metal parts or metallic sprays on them at all.
Of course, that thread is not going to help you now, as you've already dunked your case and have experienced problems. In my case, I did the deyellowing on a rather cool day, but a day on which I had direct sunlight all day long (no shadows from buildings, no clouds at all). I therefore had an abundance of UV light at my disposal, which clearly sped the deyellowing process along for me.
I did "dunk" my mouse plastics and some keyboard keys, since I didn't need so much of the liquid to do that. However, none of those pieces contained any metal, unlike the inside of a company Mac housing. And before I applied the gel form of Retro/LumpyBright to my SE/30's housing (on the outside only, not the metallic spay on the inside), I was careful to remove the Apple logo on front as that is paint on metal. And because the H202 I used was the normal drug store 3% (i.e., weak) stuff, I did not experience any degradation of the keyboard key silkscreened text or the text silked on the front of the SE/30 housing.
Whether you have destroyed your case or not is something we will have to determine after seeing your photos. But it is clear that you should stop the deyellow process right now to avert further damage to the shielding on the inside. I suppose that some people may contend that you really don't need to worry about the shielding even if it peels off. And that is true. The FCC won't track you down for spraying RF interference in your own home. But if you are like me, you may be bothered by the knowledge that you destroyed even an unseen part of your Mac, in which case you should revert to the gel deyellowing method instead of the liquid form.
To everyone reading this, if you have any bit of metal on something you wish to deyellow, consider well what kind of metal it is because it will be impacted negatively by the deyellowing process. In such cases, the gel form of RetroBright is your only realistic option. I know first-hand it is more troublesome that the liquid version, as you have to reapply it once an hour throughout the day. But it will give you the best results without damaging your metallic parts. Reserve the liquid form only for 100% plastic pieces, with no metal parts or metallic sprays on them at all.