Oh that's an amazing problem to have! I wish I had that! Not to disregard your question at all, but oh I would've loved a 7.30am lie in. I've told DD since she was tiny that since mummy doesn't work anymore we don't have to get up at the crack of dawn, but she's never listened
To answer your question.. Yes, sometimes fixing a BT and wu time can regulate a LO somewhat. I think many on here just work in the vicinity so say roughly a 7-7.30 BT and between 6.30-7am wu. You can be strict about it, I was, probably that's why she never lies in now
When you leave him in the morning how long does he sleep for? Some are happy with a later wu and later BT, others like myself prefer an evening to ourselves.
The other thing to consider is what time he's going to bed at night? I mean if he's not going to bed until 9.30pm, yes it might be mean waking him at 7.30, whereas if BT was 7 or 7.30pm, I think I would wake him if it were me.
Would you like to post your easy so I can take a look and see where things are going wrong for you nap wise? Ideally the last few days as an example rather than what you're striving for. To include any NW's, how long to resettle, nap duration and need to resettle, temperament on waking up from a nap etc. I think that'll really help me answer your question for you properly xx