A womens frame might be easier to live with, if you need to get on and off frequently and have a bulky backpack. Pre-virus, you could hardly give away a lot of 90's vintage budget end MTB's and hybrids. Other than being durable, the most important feature of any sort of transport hack for use in London is it needs to be as unattractive and worthless looking as possible. Normally when people look for a bike, they try to get the nicest looking machine for their money, but for deliveries and station commuting you want the opposite, but at the same time you want sound mechanicals that will stand up to intensive use with minimal care.