Can the effect of a certain devil fruit last through the effect of another devil fruit? Just to make it easy to understand my question here is the example below :

Suppose a person X                                               

A User of the Modo Modo no Mi use his/her DF ability and make X younger by 12 years,                                                   

now another DF user (lets say) of the Toki Toki no Mi use his/her DF ability &amp; sends X (who is 12 years younger because of the effect of the earlier DF) into the future...                                              

my question is that, will the Modo Modo no Mi maintain its effect on X who was sent into the future or not ?
There are no known facts at the moment that support which way is the correct one.

But if I am to make an educated guess, I think the answer is no. I think that most Devil Fruits in One Piece have an "ability range" meaning that if one can manipulate the objects near him, they will remain modified as long as they are in this "range" of the Devil Fruit.

For ex: The DF of vice-admiral Tsuru, Woshu Woshu no Mi, allows the user to literally "wash and hang out to dry" people and objects as if they were clothes. I can't imagine that if she chooses so, those people will remain like that for the rest of their lives. Same goes with Trafalgar Law's ability or Sugar from Dressrossa. They have to be in a reasonable range so that their respective DF powers work.

At least that is how I imagine the OP world works because otherwise it would be total chaos and we haven't seen any other character that had traces of a Devil Fruit ability on them that was used in the past (not their own DF powers of course). And to answer your question, the person sent in the future will automatically revert to their original nature and nullify any other DF abilities that were used upon them.