got a plumbing question for the experts,

currently, this is the plumbing i have in upstairs bathroom:

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\________________|__________________
up for toilet vent to attic to roof drain down

i would like to move the drain for toilet (move the toilet) more to the left
(on the schematics) this invoves bringing the horizontal drain up by about
8" to cross a structural beam (the part after the vent). Is is acceptable
to do this for toilet drain? It would be 2-45° elbows back to back (i don't
see problem with this, as long as the overall slope is maintained).
If this is done, does the vent have to be relocated - ie would it have to
come up from the new elevated section , or can it remain as it is?
the new plumbing would look like this

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\___
\______|_________

or like this:
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\___|
\_______________


Thanks.
m.