Personally I don't think Dele should be given a penny more by Everton.
However. What I find strange however is that the supposed "contract clause" is certainly not legal, even if all three parties signed up to it.
Restraint of trade clauses (which this clearly is for Dele) are pretty much unenforceable and have been for decades. They only have slight weight if there are commercially sensitive issues, none here.
Dele himself could easily claim this even without citing his mental health issues documented over the last few years.
Pay as you play only though, even if Spurs get the bums rush.