For me, 20% less pay = 100% less saving at the end of the month.

Rather than keeping all your other expenditures the same and reducing your savings outgoings by 100% each month, what about reducing all your expenditures by 20%?

Unless your income and outgoings have been fixed at their exact current levels for your whole life, there's nothing magical about their current values and they could change?

Having 50% more free time and ~45% (20% of each 2 day weekend and none allocated to the additional weekend day) reduced financial means to enjoy it sounds like a pretty bad tradeoff.

With another day at hand you can paint your garage door on our own etc. I find the costs quite elastic in that sense given the work load.

ok, but then your free time isn't +50% because you're spending that extra day on labour to now compensate for the lost savings.

Don't get me wrong, both myself and my wife are both working 4 day weeks after the birth of our son (culturally, that certainly helps the discussion), and that extra flexibility let's you choose the option that's best for you, but there is an opportunity costs trade off between them all...

Painting a garage door is very different work than staring at a computer screen and interacting with coworkers. Some people enjoy physical labor occasionally as a nice change of pace.

Yeah physical labour on my own property isn't work to me either.

Alternating your "main" job with other physical work, perhaps outside, is much more healthy both physically and mentally.