There's a large variety of first aid manakins on the market these days. Some are inflatable and analogue, others are solid and analogue, and others are solid with Bluetooth functionality (containing batteries).

If you're buying one, there there are plenty of analogues models to choose from. If you're using a training company, it would pay to check what manakins they use.

I am struggling to imagine how a resus manikin could be "dangerous in a confined space". Personally, I have never felt threatened or endangered by a manikin. There was once a model of human-realistic weight that was suited for practising Pole-top-rescue. That test-dummy could present a danger to a Lineman on the ground, if the prescribed method had not ensured they were standing clear. I am supposing that a trainer may place such a manikin in a defined confined space as a rescue and/or extraction exercise??
If my work took me occasionally into a confined space, I believe I would consider the danger of there being no knowledgable and trained co-workers near me, much greater than a first-aid provider's opinion that some danger existed in training my workmates.

Hi Sherralynne - A quick question in Co-Pilot provided these answers.....

Using a manikin for first aid training in confined spaces can be dangerous for several reasons:

1. Limited Space: Confined spaces often have restricted entry and exit points, making it difficult to maneuver a manikin and simulate realistic rescue scenarios.

2. Atmospheric Hazards: These spaces can have poor ventilation, leading to the buildup of toxic gases or a lack of oxygen. This can pose a risk to trainees who might not be adequately protected.

3. Physical Hazards: Confined spaces can have sharp edges, low ceilings, and other physical obstacles that increase the risk of injury during training.

4. Emergency Situations: In a real emergency, rescuers need to act quickly. Practicing with a manikin in a confined space can be challenging and may not accurately reflect the urgency and complexity of a real-life rescue.

5. Psychological Stress: Training in confined spaces can induce stress and anxiety, which can affect the performance of trainees and potentially lead to mistakes.

It’s crucial to ensure that all safety protocols are followed and that trainees are well-prepared for the unique challenges of confined space rescues.

Only your first aid provider can clarify their reasoning, but they may be concerned that using a mannequin in a real confined space could block exits or encumber trainees, leading to a real emergency. Navigating a confined space unencumbered is very different from doing so while handling a heavy dead weight.

Thank you A Rowe (sorry, don't know your given name).
I had a quick trawl through the millions of entries in the university databases (search terms were (CPR AND confined AND space) and found 3,141 citations. Many were not really relevant but 19 seemed a bit helpful. One published in 1996 was useful but not really about CPR (citation below).
The following is a quote from the article:

"If a crew is working, does the first aid kit stay behind the seat of the truck? Sites are often left without any first aid supplies when the crew truck leaves for lunch, supplies, or breaks.
Common first aid items extremely helpful in a confined space situation include: antiseptic spray or wipes, an assortment of bandage supplies, gloves, elastic bandages, tourniquet materials, portable eyewash supplies, and an insect/snakebite kit. If CPR is required on site, protection from contamination in the form of a CPR pocket mask should be available."

This gives an interesting comparison between co-pilot and the databases! How do we know that co-pilot correctly interpreted all that it found? And would you rely on co-pilot in your defence in the District Court?
Johnson, L. F. (1996, April). Providing first aid assistance in confined spaces: the Journal of Industrial Health, Occupational Medicine and the Surgery of Trauma. Occupational Health & Safety, 65(4), 34.