How to set beatgrid when tempo is not consistent?

Hi everyone,

Normally the tempo in Drum & Bass songs is consistent throughout the song, even during breakdowns. However, I've got a couple of tunes in my collection in which the tempo is not consistent throughout the song. They start at about 174bpm, then comes the breakdown during which the song slows down a lot, then it builds up again to a drop at 174bpm.

In may of these songs, the beatgrid is fine, it obviously is messed up during these slow breakdowns but the producers made the song so that the drop after the breakdown fits in the overall beatgrid. However, in some of them, the drop after the break doesn't fit in the overall beatgrid. The beatgrid doesn't pick up where it left before the breakdown, so to speak (if you get what I mean). Here's some examples (YouTube links):

Dirtyphonics - Vandals

Drumagick - Ultra Bass

E-Z Rollers feat. Sharon Brown - Midnight Express

Elisa Do Brasil - No coincidence

Sonic & Silver - Rocket Launcher

L.A.O.S. - GTGD

What can I do to get the beatgrid right before and after the break in these songs? Is there a way to set two separate beatgrids in one song?

Looking forward to your input, many thanks in advance!