Blasphemy interacting with support gems

I've already seen some posts about this interactions, but I'd like to bring some clarity (pun intended) to some things.

Blasphemy, right now, is a skill that takes Curses and turns them into Auras. However, it also takes the socketed support gems and, apparently, applies them to all socketed Curses. That is if there is a Curse already socketed, if there isn't, the game doesn't allow you to socket Curse related support gems. Except Hightened Curse (???).

All of this works, more or less.
For example, Magnified Effect makes the radius of the Curses bigger, thus making the resulting Auras bigger. The problem is that not all support gems work as intended.

Im going to list the support gems I have tried, each one with Enfeeble, and each one inside AND outside of Blasphemy.

Hightened Curse:
This one augments the effect of your curse by 25%, and is displayed correctly ouside of Blasphemy, however, inside of a 8th lvl Blasphemy, this makes the curse effect modifier go from -47% to -34%. Im not sure, but considering the ouside version seems to be additive, it looks like the numbers on this one are a little funky.

Decaying Hex:
This one, like the previous, displays a new sufix in the details page when you add it outside of Blasphemy, and works just fine on its own. Inside of Blasphemy though, the added sufix in the details page is there, in Enfeeble, but the effect does not apply, there is no damage beeing done.

Impending Doom:
Oh boy this one. Outside Blasphemy, in the details tab, this gems adds a sufix that reads "Trigger Doom Blast on Curse Expiry". And it works just fine. Inside of Blasphemy, not only does the gem not work, it also does not appear in the details tab inside Enfeeble like Decaying Hex does.

Encumberance:
I know, this is not really a Curse support gem, but bear with me. If you have the "Zone of Control" node on the skill tree, your curses apply a 15% Hinder effect (aka Slow). This node does not show up in the details page of Curses once you get it, but it does work as intended. Furthermore, If you add the Encumberance support gem to the Curse, the Slow Magnitude IS taking effect, even if it does not show up as an added sufix in the details page. So, similarly to what happens to Impending Doom, this "invisible" sufix is not beeing transfered correctly into Blasphemy, and thus, is not appling the Slow Magnitude to the effect of the node.

I have not tried other support gems for now, since I'm only working with lvl 1s for now, but things like Ritualistic Curse I doubt should be working incorrectly, since that one also changes the area, just like Magnified Effect, and that one does work just fine with Blasphemy.

I also would like to add that I have only made testing with a single curse since I only have 2 available sockets on Blasphemy for now, and I cannot confirm If, as others have said, multiple Curses are not beeing applied together.

Thanks for reading all the yapping, and I hope I've made myself understandable.