Multiple transactional publication: pros and cons
Make sure both of these settings for your publication is set to False which is the default.  It these are set to FALSE and you DO NOT reinitialize your subscription snapshot should only be generated for new articles.

If you are changing any portieres of the article you have to reinitialize and recreate full snapshot. 


  [ @immediate_sync=] 'immediate_synchronization' Specifies if the
  synchronization files for the publication are created each time the
  Snapshot Agent runs. immediate_synchronization is nvarchar(5), with a
  default of FALSE. If true, the synchronization files are created or
  re-created each time the Snapshot Agent runs. Subscribers are able to
  get the synchronization files immediately if the Snapshot Agent has
  completed before the subscription is created. New subscriptions get
  the newest synchronization files generated by the most recent
  execution of the Snapshot Agent. independent_agent must be true for
  immediate_synchronization to be true. If false, the synchronization
  files are created only if there are new subscriptions. You must call
  sp_addsubscription for each subscription when you incrementally add a
  new article to an existing publication. Subscribers cannot receive the
  synchronization files after the subscription until the Snapshot Agents
  are started and completed.
  
  [ @allow_anonymous=] 'allow_anonymous' Specifies if anonymous
  subscriptions can be created for the given publication.
  allow_anonymous is nvarchar(5), with a default of FALSE. If true,
  immediate_synchronization must also be set to true. If false,
  anonymous subscriptions are not allowed on the publication.


My personal preference is to group articles into multiple publications. That way even you have to reinitialize subscriptions and generate new snapshot you can run multiple jobs at the same time. You will need to make a choice if you want shared or individual (per publication) distribution agents.