Hi,
since you took the time to comment on my draft and I just happened to stumble accross yours. I thought I'd leave my opinion.
I understand, that this is the raw version of your SCP, so it is bound to have some errors. So I'll start from the top.
From your description I don't think your SCP is Keter-class but rather Euclid, because first, it can be effectively contained if the containmet procedures are followed correctly and second, because it does not pose a threat to humanity at large.
I also think the style you write in is a bit repetative. Try to reffer to your SCP as "the object" or "the specimen" once in a while instead of just "it" or "SCP-XXXX".
Finally it feels like there are some, well let me call them "holes", in your draft. It's like little bits of unclear or missing information here and there. For example: what if there is no fitting host in close enough proximity? Or: How long is the active state of your SCP precisely?
There also are some minor errors in tonation but I think that's subjective
If you would allow it I would take the time to make some changes here and there and fix some errors without completely taking appart your concept, which btw I think has a whole lot of potential. I'd say consider it.
Anyway, have a nice one :)