It totally makes sense to continue to adapt those rights to changing environments. Like the proposed "off-times" while working from home.
What I don't like is the tax-system getting ever more complicated. Now we are talking about a 600 € deductible for working from home, which is more easily attainable than the already existing deductibles for your home office. Both will exist alongside each other. Then we have deductibles for commuting to work, which of course is counter-productive to deductibles against climate-change and makes no sense combined with the deductibles for staying at home. Why deduct both possible options, if you could just lower the tax-rate?
The existence of these rules, does not make the system fairer, it just makes it more and more complicated. You will never be able to complete it. A simpler system would benefit more people. If you earn less, it's likely you won't be able to apply for all these things anyway or properly fill out your tax statements. So I think we desperately need a shift here: Abolish all of these rules, at least the ones, which are actively harmful. If you really want people to keep more of their money, lower the tax-rate!
I would also reduce worker-protections for the highest earners, especially freelancers. At some point they are just getting in your way and are not protecting you, but actively hindering your progress. So I would propose, that both parties get more freedom to design their contracts, as soon as the employee has net earnings of say the top 10% or top 5%.