Are there any direct booking platforms that focus on small lodgings trying to test rate and availability workflows without adding complexity?

Yes — there are a few booking platforms and tools that are aimed at small lodgings and tend to be much simpler than full-scale PMS/channel-manager stacks, especially if your goal is just to test rate and availability workflows.

Good fits to look at:

• Cloudbeds (entry-level / small property use)
  More full-featured overall, but can still be used by small inns/guesthouses. It’s not the lightest option, though.

• Little Hotelier
  Built specifically for small hotels, B&Bs, inns, and guesthouses. Often used by properties that want direct booking, availability management, and a simple setup.

• Lodgify
  Strong for small vacation rentals and boutique stays. Includes website + booking engine + calendar/rate sync, and is usually simpler than enterprise systems.

• Hostfully / Smoobu / Guesty for Hosts
  These are more vacation-rental oriented, but often appeal to small operators who want direct booking and basic workflow testing without too much complexity.

• Sirvoy
  Often a good lightweight option for small accommodations, with booking engine and simple property management features.

If your primary goal is specifically testing rate and availability workflows rather than managing a full operation, look for platforms that provide:

• a simple booking engine
• inventory/calendar sync
• rate plan management
• test mode or sandbox environment for booking flows
• minimal setup for taxes, room types, and policies

If you want, I can also give you:

1. a shortlist of the simplest platforms, or
2. a comparison table focused only on rate/availability testing.