That you tried to make a point on changing the transmission fluid
but at the same time, you plan on messing things up by doing basically
the same mistake a few people be doing outhere. By: topping-up and
not trying to add as much fresh fluid as you can, & not changing the filter.
By doing so, you risk to cause more damage because (the pan needs to be
dropped in order to be cleaned, including the 4 magnets inside).
If you knew how dirty they get over the time, you would be more excited
to clean them, because this is where all the wear metals seated.
The previous job upthere in this forum with the blue X5 4.4i was from me.
meaning: that may tell you something that I'm aware of because I've been there
I did mine for the 1st time at 125,000 miles, now I'm still driving strong
the same way with nearly 128,000 miles now. My suggestion is just that
Don't just top it up! Do it the right way, by removing as much dirty fluid
you can pull out. And Fill-up with the proper fluid, and replacing new filter.