Toddler overly affectionate with baby

He's old enough to understand boundaries. You can talk to him about how to be around the baby before he interacts, but you can also help him during their interactions and if he has a hard time maintaining his excitement then he needs some time away from his baby brother. Hell learn

My stepson is a similar way with my baby. Yesterday, he pressed down on his head with a toy. Prior to that, I gave him one warning after he put a blanket over his little brother's head (who screamed) that if he made his brother upset again, he would go in a timeout for 4 minutes, and have to apologize afterwards. I followed through with that. I've learned that giving him chance after chance to have soft hands is not effective at all.
If this doesn't fall in line with your definition of gentle parenting, you can let me know and I'll delete my comment. I'm not exactly sure what gentle parenting entails.

Use assertive statements and offer two acceptable alternatives. If possible, find something he can do to satisfy his need to show love to the baby.

Also be mindful that it could (at least sometimes) be an attempt to get your attention. If you are (understandably) focused on the baby, but react to him when he gets too handsy with the baby, he may be subconsciously using that as a way to connect with you.
Toddlers don’t really distinguish between negative attention and positive attention. They will just repeat behaviours that result in an interaction with the parent.

“You want to show your brother how much you love him. You can show your love by giving him a kiss on the face or rubbing his feet. Do you want to give him one kiss or sit by his feet and rub them for a few minutes?”

“Notice how baby is crying when you squeeze him like that? That’s him telling you ‘stop, I don’t like it.’ You may not hug him if he is crying. Would you like to take one step back and sing him a song or go get your stuffy to hug and cuddle on the couch?”

Also, make a point of descriptively praising when he is handling the baby gently or stopping when the baby fusses.

“I noticed you only gave baby 2 kisses and stopped when he pushed your face away. You did a good job listening to him and giving him personal space.”

“I saw you rub baby’s feet when he was sleeping but didn’t wake him up. You should be proud of yourself for using gentle hands to show your love. Let’s do a puzzle together while the baby is sleeping.”

So I have a 2y9m old and a 4mo. She was 2y4m when he was born. I always wanted to encourage interactions as I was worried about jealousy between them.

She absolutely loves her brother but is also so excited by him and sometimes doesnt realise her own strength when doing things.

The approaches I have used:

If she is doing something I don't like I redirect by giving her two choices that I know she likes to do with baby brother.

She currently loves screaming when he's down for his naps and bedtime sleep so every time he goes down I announce it and get her to repeat the following: baby brother is going to sleep now, what do we do when he is sleeping? Be quiet. And if you want to come into mummy's room what do you do? Be quiet? That's right."

She also got into the habit of putting her foot on him at about 2 months old. I didn't react or shout. I just told her why she couldn't do it, how it would hurt her brother and why he would cry. Would she like it if mummy or daddy did the same. She did it twice only.

I’m gonna try this, thanks for giving examples it helps a lot. To be honest I do spend a lot of time with baby, but the other day we had to get an uber to visit my mom and he refused to get out and cried because he thought I was going to leave his brother in the uber. He waited for me to take out the car seat before getting out. He also wakes up in the middle of the night, leaps over to his brother and kisses him, then goes back to sleep. He really loves his brother and I’m petrified of ruining their relationship.

no your comment is fine, but the Montessori way focusses on assuming the child means well and teaching the correct way, as opposed to punishing or focusing on what they did wrong.

Oh, interesting. Is that the same as gentle parenting, then?