Good point!
It depends which of two exactly opposite effects you prefer.
On one hand sometimes inward-facing 'to-inside-open' leg-cuffs offer just that bit of capacity to swallow leaking drops and so keep them from running through and build wet stains to be visible from outside - maybe just for a few seconds - but these could be enough time to react to avoid an accident - such as flying to bathroom for paperdrying or changing...
On the other hand I wear plastic panties just for fun (that wasn't always the case) without diapers so I often wear them with the seams facing out-wards. I think most look reversed almost the same and why should my skin be in contact with all these cutted plastic edges when I anyway wear the plastic panties hidden underneath? But the mainthing: Reversed especially the leg cuffs (which covers the elastics) are facing outwards and so are prevented from flooding with whatever fluids. This keeps the cleaning of the plastic panties quite easy - 'two-sponge-cleaning' (hygienesoap/water, not too wet) - towel-wiping - and paper-drying with a common desinfectant-spray ...each done with fully stretched waist and leg cuffs! This gives quite perfect results... it's plastic, not textile.
You know, these cuffs with all their plastic ruffling (especially if there is open access to the elastics) are quite a 'weak point' of plastic panties. Bacterias easely can establish in these tight folded up areas. Even washing/rinsing can cause the same (especially if elastics are firmly closed) - because such cuffs then act like watertraps. So they need special attention - pressing them out between towels - sometimes even need perforating the outer ends for better water/air-exchange - allowing the cuffs and elastics to properly dry.
An other point is fun - feeling! - the tactility of these surfaces - PVC in most cases has two different sides of which one is smoother while the other is more 'grainy' (sometimes like a slight texture). As long this texture is pleasant (non-agressive 'round grainy') - no problem - wonderful! - it even can (depending to your temporary needs) offer more or different stimulation than the smooth side.
Most TPU (and EPU) have two equal sides of most fine smooth 'micro- (or is it nano?) -texturation' even when looking shiny and glassclear - (sometimes it needs time to adapt to enjoy when coming from PVC) - it's finest sensitivity which maybe needs more diluted* (thinner) lubing to be nicely felt! ... But here are some thicker TPU which can have a very 'dry' side (can feel like rough paper - agressive - 'pointed grainy'). After some time these really can hurt sensible skin when worn direct on it. To avoid this - but just for short - more viskous (thicker) lubing is needed. After that (if you need to experience) you better change for the smooth side facing inwards as soon as possible!
*(because TPU is waterproof & breathable it keeps fluids in but lets waterdamp evaporate through it - which cools it - but also allows to dry lube. So for pleasure it needs relubing or 'lube-re-diluting' from time to time. Diluting waterbased lube is easy enough. Simply waterspray inside (I use empty deosprayers for this, refilled with water that was pre-cooked & re-cooled (again: Hygiene!)
So, in developping this passion you will find that almost every plastic, every PVC and TPU (and Latex - PUL - Polymere-coated-Polyester etc.) will feel different - and there actually should be a corresponding lubing - this will offer a lot variations - and if the combination is really matching your actual feeling it gives you wonderful pleasure... OMG! ...there is almost nothing else providing you that incredible (even insanely) sensitive stimulation that let you feel yourself in such a wonderful way! You will notice by your bodys lust and precum responding...