• None of the light (low profile) harness used for rock climbing seem to have openable buckles for waist and legs.

Black Diamond Equipment - Men's Momentum Harness - Anthracite - Large

https://www.amazon.com/Black-Diamond-Momentum-Harness-Anthracite/dp/B081BB25N7

• $65

Black Diamond Equipment Big Gun Rock Climbing Harness

https://www.amazon.com/Black-Diamond-Harness-Large-Tequila/dp/B001AQJNRY

• $130
• https://www.blackdiamondequipment.com/en_US/product/big-gun-harness/?colorid=5124

PETZL CORAX

https://www.amazon.com/Petzl-CORAX-Harness-Adjustable-Mountaineering/dp/B08PVYVHMJ

• $70

PETZL ADJAMA

https://www.amazon.com/PETZL-ADJAMA-Climbing-Harness-Large/dp/B08PVXHX35

• $90

Petzl ALTITUDE Harness - Lightweight, Compact Mountaineering and Ski Touring Harness

https://www.amazon.com/PETZL-Altitude-Ultralight-Harness-2020/dp/B083G9SWN9

• $90
• Easy to Take On / Off