I'm leaving my job soon, and before I go, I'm wondering if I should give some feedback to my manager about things I was unhappy with while here. He's not the reason I'm leaving (though is partially the reason I started looking for something else), but I feel there are things he could've done better as my manager, and perhaps if I share the things I was unhappy about, it might make life better for the next graduates that join the team.
I was largely unhappy with the lack of contact and feedback from him; a lot of the time I was working on poorly defined tasks I had to pick up from scratch with little support. He'd seldom or never check up on how I was doing, and as such it was very hard to tell if I was doing well. As an inexperienced hire, I expected more support and training. I've also often felt under-utilised, ignored and bored. I admit I could have been more forthcoming in going to him when I needed things, but the times I did go to talk to him, it often felt like little came of it.
The things I'd suggest to him would be to put aside more time to check up on new (inexperienced/grad) hires - just a brief 'how are you doing?' once a week might've made a difference. Being more clear about what was expected in what timeframe, how to get help with it/who to ask and what resources are available would've been great. Basically, greater communication (from both sides - but I feel that, as a manager, if the employee isn't forthcoming, the onus is on him to open up that channel).
Is it a good idea to try and mention something to my manager before I go? Or should I just drop it and move on? (I don't think I'll get a formal exit interview - we had a meeting that I thought might be something like one, but it was focused entirely on work handover and nothing beyond that.)