you could also use *gasp* a metal connector to hold the tie down.

i can't say that i'm a fan of that huge lap you are taking out of the tie. what does the relish outside of the plate do for you, as all the theoretical thrust is taken inside the end of the tie, at the inner corner of the rafter / tie connection (assuming that this works like a truss and we simply don't load the king post to the tie) i also see that hunk just checking and falling off.

and if this is an enclosed and insulated structure running that into the wall will create a thermal bridge and open up (depending on how it is detailed) a path for vapor drive.

without studying the rafter / tie connection i'd be hesitant with just the MT, i'd probably use a girt shoulder and lag it from the top, or a girt shoulder and tenon combination sans lags, although this removes more wood than necessary.

without running numbers a solution might be (assuming an enclosed frame) to house the tie into the plate with a full 1" housing so the tie sits on the post. then run all thread with a timber lock / bed bolt connector from the tie through the plate, about 2-3" down from the top surface. the post gets a tenon into the plate, oriented to the outside with the tenon staying below the steel.

but - all that is dependent on piece size, as I don't think we know the size of the posts nor the rafters and tie, assumptions being 8x stock.

and in terms of wind loads - if you are enclosing this the plywood sheathing and wall system will do more to help with the shear / wind than the timber braces.