I have had feeding plans with both my girls. With DD1, i was doing the 8-10 times a day pumping and only ever got 40ml total at a time. With DD2 (currently 6weeks and only made her birth weight back at 3w exactly), I'm getting exactly the same as you (around 25ml) when i pump after a feed. I'm only doing one pumping session a day as i cant manage anymore with a toddler in the mix! Then 8 x feeds at the breast and formula top ups after each breastfeed.
The lactation consultant i have been seeing suggested a couple of things if i couldnt pump more than 1 or 2 times a day - 1) dont put baby to the breast for one feed (give her a full formula feed instead) and use the time saved to do a full pumping session to really try and empty the breast. I do this lateish afternoon when we always had a fussy breast feed anyway, and 2) try doing a power pumping session in the evening. This is pump for 20mins, rest for 10mins, pump for 10mins, rest for 10mins and pump for 10mins. Its supposed to mimic cluster feeding. I dont always manage these every day, but try and drop them in when i can.
I have seen a bit of an improvement this week, but its hard to tell if its due to the above techniques, or if its because at 6w, DD2 is now getting better at feeding and developing a stronger suck.
If you haven't had a look already, see if the kellymom website is helpful for you. Its American but has so much information.
Good luck - pumping is such hard work (emotionally and physically!) I did it for 6months with DD1 and it nearly broke me. This time around, im much more relaxed about switiching to formula fully if we need to - hoping to make it to 3months but would like to prioritise getting out of the house a bit more this time! You are doing a great job no matter how you end up feeding 💐