To know how many addresses you can generate from one seed you can refer to below quotation:
In order to understand, how many address could be generated from one seed we should go to the process of address generation in HD wallets.
As bitmover said, there are 4 billion children possible:
From antonopoulos mastering bitcoin:
To be exact, the 4 billions means 2^32 - 1 = 4 294 967 295 (this was a limit designed in HD wallets).
The path format of HD wallets is
m / purpose' / coin_type' / account' / change / address_index, where account, change and address_index are dependnecies for address creation based on master private key (SHA of the seed).
Let's say for bitcoin it is m/44' /0 / account' / change / address_index
account and
address_index could be in the range from 0 to 2^32-1 (2^32 total combinations),
change could be 0 or 1 (change address or not), so 2 total combinations.
Hence, the total number of possible combinatins is 2^32 * 2^32 * 2*1 = 2^(32+32+1) =
2^65 which is 2^191 less than the total possible private keys and 2^95 less than the total possible addresses (cinsidering hash160 function) for every address type (legacy, segwit, bech32)
So, considering the HD wallet limitation (2^32 for child and address index), we need at leat 2^95 different seeds in order to generate all possible addresses (withount collisions).
Because of the quotation above, I
pretty sure that think those wallets you mentioned does not set a limit of maximum generated address you can create in term of within the wallet itself. On other hand, if you want actual proof, you need to verify the source code on the wallet itself or maybe you can just ask their wallet devs/support about it.
