This is one of the more decent implementations of a cupholder mount. However, with anything decently sized, it will still wobble like crazy. The whole premise is just flawed. Try using a different solution altogether.
PERLESMITH Full Motion TV Wall Mount: 37-75 inch Flat/Curved TVs, 42.5" Articulating Arm, Swivel/Tilt, Holds 132lbs, Max VESA 600x400mm, PSXLF01
12 Review
Echo Spot Stand BMK Amazon Adjustable Support 360 Horizontal 40 Vertical Rotation Ball Bearings Bracket Speaker Mount Home Office
19 Review
PERLESMITH Tilt TV Wall Mount Bracket for 32-70 inch LED, LCD, OLED and Plasma Flat Screen TVs - Fits 16”- 24” Wood Studs, Tilting TV Mount with Max VESA 600 x 400mm hold up to 132lbs - Enhanced SEO
12 Review
Wall-Mounted Hanger For Echo Dot 2Nd Gen - Space-Saving Solution For Amazon Alexa Smart Home Speakers With No Messy Wires Or Screws, Perfect For Your Home (Black)
15 Review