here's my take, for whats its worth:
yes the FI processes / IT needs some work to say the least. but does it impact my overall enjoyment of the product? No. Its an inconvenience, but not a major thing.
FI's infrastructure appears to struggling due to the rapid growth of the product. i am happy for that to be the case at the moment!
they also appear to have put more of their investment into marketing rather than systems / tech. again, i am happy with that approach right now!
the collaboration with nasdaq should remedy such issues. you would hope. will that be implemented quickly? no, i wouldnt think so.
you appear to be angry due to the fact you cant re-invest your dividends straight away. my advice here would be to always keep a few quid in your cash balance (i aim for around 3%-5% of my overall portfolio). this way you can always react quick and get in at the best price where possible.