As someone with a foot in two camps, I'd say
1. GBR's failure with 1 exception to take anyone in a non Olympic Game spsport was a mistake, and disrespectful of the Games - indeed, disrespecting the event is a standing problem. I'm not saying the event is particularly surging anywhere (except italy!) but with these things sometimes the thing is what you make it. I know enough to know the very best US and Jamaican sprinters don't go to the Pan-americans, or necessarly many of the top-tier distance runners to th Africans, but I increasingly think that's a really foolish attitude for the athletes, the federations, the Olympic committees and the sports themselves. You ahve to push every opportunity you get in the modern ecosystem. For GB, this was - yet again - an opportunity missed imho.
2. The divers had the excuse that the federation made a perhaps justifiable call, and may even worked out quite well for some of the divers. The athletics had no excuse whatsoever. I maybe understand the desire to protect the stars - but let's be clear, there ain't that many stars. And if Keely Hodgkinson can do an U23 400m, for example, she can darn well do a European Games 800 (and Boffay was far from the worst level reserve, there, she was justifiable.
3. going back to 1. if Team GB/BOA are unwilling to pick in non-olympic sports then let some other organisation - a 'World Games' based equivalent, take over and do it for non-Olympic sports. It's unforgivable that GBR kickboxers, thaiboxers missed out on what would be a major event for them, and a medal winning opportunity in some cases, becuse the BOA has no interest in their non-Olympic sport - not least because going forward, non-Olympic/'World Games' sports are likely to be an increasingly important part of the event, for the variety they introduce - as an Irish + GBR fan, the last two days of the kickboxing was incredibly exciting because the Irish cared enough to send people - and won medals that put a real gloss on their games.
4. The various European Feds and the EOC need to come together and stop fighting for dominance - the EOC has no event without the sports feds, but the sports feds have few (and possibly fewer re European Championships model) opportunities to get 'casual' eyeballs on their events, and the EOC event, if done right - cheaper, continued regional model, continued non Olympic games sports, extended OG qualification spots - is a perfect opportunity to 'create value' as they say, and eventually make separate money for the European Feds rather than rely on the trickle down from the IOC and global feds..