If you make manual changes to the condition of the racecourse, example: Turf course from good to yielding, does it have any difference or effect on the factors calculated and then shown on the html reports?
If you change a race from turf to dirt (or vice versa) then yes - you'll get a completely different look at the race. The surface change will drive a completely different set of numbers being pulled from the ImpactValues Table - and you should see a different JPR and UPR as a result.
If you leave the surface the same - but change the condition of the surface - then your JPR/UPR numbers remain the same - but...
If you have active UDMs based on the the condition of the surface - for example UDMs where you've used the TKIN Preset Filters requiring YL, MY, SY etc as the track condition - then any horses that qualify according to the factor contraints in such UDMs have a chance to be flagged by those UDMs.
But if you leave the condition of the surface alone - then any off track UDMs that you have won't get the chance to flag horses.