Interesting.
To clarify the point about legal tender:
"Legal tender" refers specifically to acceptable forms of money which MUST be accepted to settle a debt, in law.
The statement in bold is incorrect. The creditor is not obliged to accept payment in legal tender for a debt.
(Technically legal tender applies only to debts paid into a Court, but equally it is likely any Court case for failure to pay when legal tender was offered would fail - though I don't know if that would apply to a Byelaw or RoRA prosecution as these are rather special cases)
This statement is also incorrect.
The relevance of legal tender where a debt exists is if payment of the exact amount due is offered in legal tender. The creditor need not accept that payment, but it is then open to the defendant to any subsequent debt action to plead a defence of tender before claim.
The Civil Procedure Rules then impose an obligation to pay the amount previously offered into court in order to avail of the defence. This rule is not limited to debt claims though.
Mere payment into court would therefore (by itself) be too late in order to found the defence. Nevertheless, if a payment into court is made during the claim, the creditor might potentially be penalised in costs should he continue with the proceedings.
Finally, in Scotland the court will normally be willing to repel a cause if the creditor refuses a reasonable offer of payment, even if this payment is not offered in legal tender (e.g. offering to satisfy a debt of £100 with a £100 note).