Sometimes back I happened to research on comfortable and ergonomic remote control design. And I will share brief summary in what I find, and that may be help in your design start-up

• Remote or remote handling position should be cylindrical or oval in shape.
• Preferred enclosure diameter 1.5". While recommended Min 1.2" and Max 1.8".
• Remote Length - Handle that is too short can cause unnecessary compression in the middle of the palm. The preferred handle length 5.5" with Min 4".
• Rounded/Padded handle will reduce any soft tissue compression.
• Avoid extreme and awkward joint positioning to the hand.  

in addition to these

Some specific ergonomics considerations for remote control design might include:

• The size and shape of the remote control should be comfortable to hold and operate, with buttons and controls that are easily accessible and not too close together.
• The placement and function of buttons and controls should be logical and intuitive, so that users can easily find and operate the features they need without having to look at a manual or instructions.
• The labels and displays on the remote control should be clear and easy to read, with high contrast and good visibility in a variety of lighting conditions.
• The remote control should be lightweight and balanced, with a low center of gravity, to reduce fatigue and strain on the user's hand and wrist.
• The remote control should be durable and resistant to damage, to ensure that it can withstand regular use and handling.

Overall, ergonomics considerations are an important part of remote control design, as they can help to ensure that the product is comfortable, safe, and easy to use. By taking these factors into account, designers can

Check this out

https://wiya3d.com/ergonomics-for-product-design/