Hello,
The error you report is not an exception but a database error and I do not think it indicates that your DB cannot handle this charset/collation.
Please keep in mind that coin adapters are an abstraction/encapsulation of crypto wallets, and they do not touch the database directly.
The collation is set to latin1 to match the character set which is also latin1 for fields that do not require Unicode. This includes coin symbols, addresses and transaction IDs.
Latin1, as you know, has one byte wide characters and this saves space. If four bytes were used as you suggest, this would cause problems with the size of some table indexes. This is why latin1 is used. It is unlikely that your database cannot handle this basic collation and charset as it is the most basic one – essentially ASCII.
Instead, it is possible that you have run on some of the block.io service limits with a free account and this is probably why you do not get new addresses. At this point in time if I were you I would prefer to use the CoinPayments adapter which has no such limitations.
In any case the SQL UPDATE wp_wallets_adds SET status = 'current' where id = 1; should not generate an error, and it does not on my machine. This is curious. Which DB are you using? Can you show me SELECT VERSION();?
kind regards