The P&S rules effectively apply to championship and premier league. So the stuff below that doesn’t get taken into consideration.
On relegation from the premier league to the championship there are transition allowances which give them more leeway (allowing for the contracts that their players have I guess). So they are allowed higher than the £41.5m total 3 years loss. Effectively they have, I think, £35m allowed each year they were in the premier league and then £13m for championship. So if they made a loss of £25m last year, they have £13m plus the £10m they didn’t use last season. I think, anyway. That may be wrong.
On promotion to the championship it starts as year 1 of the rolling 3 years. I agree with you that that is bollox btw.
In league 1, I believe that owners are allowed to top up (inject equity) to get them over issues.
Birmingham and Wrexham are both able to spend a bomb this year.