SAP XI/PI - SPS Upgrade & transport Movements

Hi Experts,

I have few Queries related to SPS upgrade in SAP XI/PI and Transport movements.

For example i have 4 environments in my Landscape say A  ->  B -> C -> D.

Current version of XI -  A is 7.1 SP 13 ( Upgraded )

Current version of B,C,D are 7.1 SP 08 (Yet to upgrade ).

At this point of time if i move my transports ( both ID and IR objects) from A to B (I.e from Higher version to lower version) will i face any issues ?

what is advised to move the transports successfully ? Kindly also give me few details on that.

Regards,
Ruban.S