Been lurking here for several months and have found many useful ideas, so I'll try to give something back.
One good way to build a life apart from your wife and to get out more when you have young kids is to TAKE YOUR KIDS AWAY.
Take your kids to the park, and don't just stand there like a lazy fuck; play tag, kick a ball around, make up and play silly games, engage with them. If the weather is too poor, take them to a different room in the house as far from your wife as possible and wrestle and roughhouse on the floor; use your manly strength (because you lift) to lift and throw your kids high in the air and catch them; make up fun, physical games that challenge them. Bring the fun, so that Daddy Time is the highlight of your kids' days (and of yours as well).
You really should be doing something active and fun with your kids EVERY. SINGLE. DAY for at least an hour ... so that they don't become fat fucks like you.
It is particularly important that you take your infant away from your wife for at least 30 minutes every day, to stop that constant libido-suppressing oxytocin drip, and to condition her to spend half an hour without worrying about the baby (which might come in handy when you want to have good sex with her). After baby nurses or feeds, take your infant from your wife's arms for Daddy Time. Take them away: outside, out of earshot and out of sight, and spend some solid one-on-one time with them, or carry them around while you chase the older kids. Any just-fed infant can go for at least 30 minutes or an hour apart from Mommy, so take your baby away to bond with you, and to do fun things they don't do with your wife.
By building your own unique life and activities with your kids APART from your wife, you both add great value to your family and implement Dread Level 3, and you can easily do it every day. Even better, your kids are also Dread Level 3'ing her at the same time, so she's losing that additional validation from them. There's a bonus form of "Mommy Dread" here as well; you are showing her that you can take care of the kids all by yourself (and in fact that the kids even prefer that special hour every night with Daddy over yet another hour with her), so she's not such an irreplaceable special mommy snowflake. You also get daily practice building and holding frame and setting boundaries with opponents who aren't nearly as formidable as your wife, in a fun, low-stakes context.
This is the rare situation in which your MRP interests actually align with the prevailing blue-pill paradigm; the whole BP world tells fathers to spend more time with their kids and to relieve the mother's burden of childcare, so everyone will support you in this. Thus you can implement this early in your MRP journey without overtly rocking the boat and can appeal to scientific and even feminist authority if your wife is a mommy martyr or control freak and resists, even if your frame is weak and you end up DEERing your way through to it.
Just remember, you have to disappear for the dread, so playing with your kids in the living room while she scrolls facebook doesn't help. Take your kids away ... and have fun!