You won't see any key frame markers until you click on the add marker diamond icon (John has highlighted the control panel), or add one.by changing the value of the effect from its default value.
Magix MEP product info says that key frame animation is available on all versions so I don't think your Sequoia source is the problem which might well be the case for multicam editing etc.
Some tips from my answer to a French post where the member wanted to change the level of several KF's at once ie. change one parameter at all keyframes, say the "Width" only, of a picture that was moving through the frame without changing the "Position" KF's.
After making the effect curve visible in the timeline or in the small keyframe animator timeline"-
" you can also "shift" click the first and last keyframe and all in between will be selected.
Also, it is sometimes better to click the triangle dropdown beside the effect name in the keyframe editor and select "edit effect curves" and a window will open where you can change the position of the whole effect along the timeline, the strength of the effect, and even invert or mirror the effect about an axis."
And further - where there are multiple sub parameters under a heading like Size / Position:-
"..... using the "Edit effect curves" window - click the triangle to the Left of the "Image size / position" name in the keyframe animator and all the individual parameters will appear ie. width, height, posn. etc. Click the triangle to the right of the parameter you want to change and select "Edit effects curve". Enter a pixel or % value in the appropriate Effect box and click the + or - button to change the effect for all keyframes, by the entered increment.
In your case, to change the size, Ctrl click the height and width parameter names after opening the Edit effects curve window - both will change at all keyframe points, by the entered increment when clicking + or-.