Thank you for all your answers. I will look at your suggestions in detail.

I'm not a big fan of IPQ chips, I've tried a few (4018 and 8072A) and they are much more power hungry than the competition (QCA, MediaTek).

To go a bit into detail, I am looking to replace my venerable TL-WR841N (QCA9533, 2.4GHz only) which is in the technical room of the swimming pool and which is limited to version 19.07. It has posed absolutely no problems for 1000 years since I put it into service The fact that it is inside the room poses concerns (concrete walls), the wi-fi of the outdoor Iot has a hard time passing the walls of this shed and I would of course like to be able to have an AP with a newer version of OpenWRT. Its hardware would have been more recent, I would certainly have simply moved the antennas outside the room to solve the problem, knowing that it only consumes 1.5W