Travel & subsistence under IR35

[malvolio]

In the main, I would agree with you, however, for some roles market forces will be fully in play.
If a client really wants someone, they can and will pay all expenses on top of your usual day rate.

A client really wanted the other half on, a fairly remote site recently for a 6 month contract, she said she would only agree if all expenses were on top and they agreed.

Oh yes, it can be done; I've managed it myself. But there needs to be a fairly exceptional reason - specific skills, odd location whatever - but it's very unlikely in the course of an existing engagement.

The market will shake out in time, but it will take a while. Don't forget this is not costing the end client anything so they have no incentive to change until they run out of willing suckers.