help with high LTFT at 18% ish

I am attempting to try to finalize my project car, fixed a couple of ongoing issues including a boost leak (there may be more?!).

However I am running live data to see how things are running with the car and have noticed that it has a high LTFT around the 18% mark when idle/cruising.

I have attempted to clean the maf as when I done the smoke test for the boost leak I thought it might of left some residue (though the smoke I got said it was residue free) - I cant recall the LTFT before this test though so unsure if it was anything to do with this. whilst at it I also cleaned the first O2 sensor.

I have also as of today got a vacuume tester and showing approx 19 cm-hg, this sounds about what to expect.

as this is an engine I am not used to in a car its not supposed to be in I am not sure what normal operation would be but I cant seem to identify any abnormal running issues at this point, it starts first time, initially sound a little uneven but soon goes to a steady state (takes a few seconds on cold start but bearly noticable).

As mentioned I do have some live data (forscan) in a .csv and I have added it to this post - but I am starting to run out of ideas - I dont have an CEL and it passed its MOT emmisions not long ago (pre-warm cat removed too! - no space for that). With that said I am curious and opinions are welcome on this but I have got a custom down pipe that I would call more of a swan neck as the spacing is very tight



and a custom intake run that is longer than OEM - could these be the reason the trims are out? the O2 sensor is just near the fisrt bend in the downpipe starts but the entire thing is probably not as free flowing as OEM (or at least as what I would like) would these 2 factors require a re-tune?

Any advice on what I should try next to diagnose the issue?