It's better to do the 7.5 hours, go home and come back rested the next day. Your subconscious will be working on the problem anyway.
Most European countries seem to be over the glorification of long grueling hours. In the US and Japan it's still a badge of honor how much you work - never mind that productivity in either country isn't scaling relative to the hours used.
I work in a startup with 45 top notch engineers.
There's a huge difference between being at work 12 hours a day and actually doing something productive with that time.
Japan is an excellent example of this, in their office culture you never leave before the boss does and try to be at the office before them. People spend 12+ hours at work and don't produce more than other people who work sensible hours.
Coronavirus and remote works might be a savior for that culture.
Not saying anything about whether this is a good idea or not. Just saying that I know people like this that I used to be skeptical about before.
Then one night I found out could't sleep. At all. Had to take a few pills just to get some shuteye and woke up with a shitty metal taste in my mouth every morning.
I started getting heart palpitations at odd times. Was on SSRI for a few years just to get over the burnout. Acid reflux so bad I could only eat unseasoned chicken and white rice for 6 months.
Since that episode I've learned moderation and have had a hard 8h/day policy with rare exceptions. No issues since, and my output hasn't really changed.