Yes, it is true, max leverage depends on your account balance and is calculated for a single account. So you can have multiple accounts and different leverage on every one of them. So if your balance rises and your leverage is lowered, you can transfer your funds to another account to restore previous max leverage.
That is what I do now. I have 10 accounts, essentially under a single login.
But here is a question:
Someday I might exceed 40 or 50 Btc in SimpleFX and so want more than 10 accounts to maintain the maximum leverage on each. Technically, that is quite doable, just creating a totally separate set of accounts, such as to have two sets of 10 accounts each. But is that permissible?
Basically, is there any risk I would get banned for doing so? This is doing so with only crypto funding for deposits and withdrawals, no fiat. I would be deliberately bypassing your 10 real account limit, indirectly, but I think the 10 account limit is just a programming matter anyway.