Negate Magic vs Dimensional Portal?

[Plane]

One oddity that I noticed when reading the Rifts Book of Magic is that pg 135 goes out of its way to note for the 10th level spell (60PPE) Mystic Portal ("creates a dimensional Rift") at the end that "A Negate Magic may also eliminate it"

Pg 152 makes no note for that for Dimensional Portal though.

The spell "Close Rift" always seemed to serve that purpose, but if Negate Magic would do the job, about the only reason I can see to use Close Rift would be that it has better range (100ft vs 60ft) but it's otherwise higher level, costs more PPE, and less multi-faceted, and permanent PPE for many classes to use.

Do we figure NM works to close DPs instantly like it does MPs, or are MPs a special case of minor-rift since it's a rift to another place within the same dimension (let's call it an introdimensional rift) as opposed to another one (an extrodimensonal rift or inter-dimensioanl rift as we mihgt term it) ?

Of course what this might boil down to is what the word "eliminate" does. This could refer to negate magic eliminating the SPELL mystic portal which removes the caster's control of the rift he created (the spell controls the rift to stabilize it into a portal) but perhaps the rift still remains (subject to standard Random Rift Table RNG results from RUE pg 196) and needs Close Rift to actually close the residual tear if you want to do that prematurely to its natural cessation?

[Library Ogre]

I would lean towards Negate Magic being able to disrupt a spell, but not necessarily other portals (which aren't necessarily "magic" so much as "the megaverse is weird in this location").

Random Rift opens in your sock drawer? Close Rift.
Someone uses the Dimensional Portal spell? Negate Magic will work.