I am interested in what different companies (particularly from a legal and professional services background) offer in terms of DSE for hybrid workers?

Our fully virtual/remote workers are provided with everything they need to work from home comfortably (desk, office chair, separate monitor/keyboard/mouse) and specialist ergonomic equipment (such as a sit/stand desk) if an assessment with a medical professional has recommended it. 

Our hybrid workers are allowed to claim up to £250 through expenses for equipment to use at home. However, this isn't necessartily enough to cover everything required and there is no top-up after a number of years to replace broken equipment. I am interested to see what other companies offer their employees who have the choice to either work from home or go into the office. 

You might want to define your version of hybrid (1 day / 2 days / 3days / 4 days home / office) as some firms frame their contractual arrangements and obligations in respect of time spent in the office e.g. 1 day at home no provision, 3 days + keyboard/mouse, 4 days + chair.

Don't forget that concepts of "hybrid" working need clear contractual statement for purposes such as travel and tax breaks for "home office" costs (energy, broadband etc.).