There is no purpose in sending TRIM after each delete: at worst (with a naive implementation) you would get a solid write amplification and at least your drive would be doing GC instead of serving the data.
Most of the time it's just sent every once in a while, often triggered by the schedule and/or the amount of writes[0].
[0] my current machine says it was 9 days since 'the last retrim' and T440 which 'works' as a glorified dashboard (ie minuscule writes overall) says it's 24 days.
I'm pretty sure that OSes usually send TRIM right away and let the drive figure out optimization. Wikipedia says "some distributions" of Linux turn it off but my various ubuntu-ish systems have `discard` or `discard=async` in the output of `mount`.
"last retrim" on Windows is an extra feature, because TRIMs can get dropped when a drive is busy enough. It goes through all the free space and TRIMs it again once a month.
Also even if you did only TRIM once a month, I think most of your free space would still be zero.
It's an SSD, shouldn't it be running TRIM?