when to start practical geometry?

My son will be in 5th grade next year and will be starting Strayer Upton book 2 (the beige book). He loves math and switching to this approach was one of the best decisions we made for math. I’m wondering when to start practical geometry? According to the suggested scope and sequence in Living Math, it looks like it’s recommended as a once-a-week lessons for years 5 and 6. So I bought the math guide from Beauty and Truth to help with this but then I read a thread that said fractions and decimals should be introduced before starting this. SU Book 1 ends with adding and subtracting and reducing fractions and money has given him an introduction to decimals. Does this mean he’s ready to start practical geometry or does he need to be more solid on fractions and decimals? I just want to make sure I’m not jumping the gun. To be honest, I looked at the guide and I’m feeling overwhelmed. I’m at the point now where I’m really just learning alongside my son (although he catches on quickly, thankfully). I’m just looking for reassurance that I’m on the right track with timing…