BLW and spoon feed

Our health visitor is insisting on BLW. My baby is 8months. He hasn’t been interested In anything since 6months. I’ve been putting food on the tray for him to play, sometimes he touches it sometimes he doesn’t. But recently he started letting me put food inside of his mouth. But she is saying I should just allow him to pick it up himself and eat. He is struggling with weight gain and I am just happy to put anything I can down him regardless of any system. Is it not possible to spoon feed and also do the BLW?