Just try removing the "quick remove" duals from an AS350 or EC120 - it is a serious job, engineer required. The clear-floor method of R22 cyclic design is pretty good, especially for females in skirts wanting to sit in the front. No need to avert one's eyes as they clamber around the cyclic with their knickers on display.
I did have a Japanese student who was so small that his legs were straight out to reach the pedals and therefore he couldn't get the tiller handle down to his knee. Simply fixed - he went to K-Mart and bought a rubber booster seat. Probably not legal, but it worked.
For the gaping R22 door problem, it is a simple fix. Get the engineer to fix another of those clip thingys that is already on the bottom of the door, to the top of the door. Works a charm, stops the cold winter winds and keeps the tense pax untense.
