I've never seen any regulation which specifies what type of chart needs to be carried, or used, in any private flying situation. There is not even a requirement (CAA or FAA) to carry any kind of printed chart whatsoever.
You need to possess sufficient information to do the flying, that's all.
No reason why a sketch of the IAP would not be legal.
If there is an incident then you might get done under the general clause of endangering the aircraft (can't remember the ANO #) but that would be the case only if your sketch was actually wrong.
Transport flights, under an AOC, are done under written procedures and these could specify Jepp, Aerad, or whatever.
There could be a problem in a different airspace where the regs might specify e.g. nationally published or ICAO compliant plates.