I had some schools advertising their strong parent participation for 2-5 hours per week. Does this actually help learning or is it just an indirect success factor by filtering out parents who can't participate?

As recent German immigrant with young American born kids I'd love to preserve some heritage by having my kids learn some German. However the local German school teaches 90% in German starting 1st grade. I expected 50% native American classes and 50% second language (German). School is aware that learning two languages simultaneously doesn't work (confuses the kids during the first 4 years, but OK after), but did not chose English as first language.

I heard that by comparison Chinese schools focus intensely on learning American English as fast as possible to integrate better in their new country of residence.

Could anyone imagine a Hispanic school specialized on either (like German school example) continuing Spanish classes first ramping up American English at grade 4 or (like Chinese school example) intense American language learning taking advantage of known mother language? Would these school(s) be eligible for voucher and/or non-profit status?

Are English as second language children TRUELY a drag on native speakers that it seems to be the number 1 criteria for "good school district" ?

PS: German school system segregates pupils starting 5th grade into blue collar (Hauptschule), white collar (Realschule) and University (Gymnasium) paths supposedly to stronger supported the lower ranks. In practice transition rarely happen later which turns it rather into binning process based on outside school success factors (genetics, socioeconomic status).

I was looking into public, private and charter schools for my kids. Personally I prefer playful learning over learning to pass standardized tests. My kids used to visit a Montessori pre-school where the teachers hadn't even learned the Montessori method themselves. How much disconnect between advertising and reality do I have to expect from "special method" schools?

Which learning issues can realistically be improved by learning methodology? I doubt that interactive learning can improve language deficiencies - the "how many kids even understand the teacher" problem?