What is the difference between a firm-imposed rule and a personal preference?

Firm rules come from the account automatically. Personal preferences are yours and apply to every account. When the two disagree, the guard uses whichever is stricter.

Two sources feed the same guard.

Firm-imposed rules — daily loss limit, trailing drawdown, maximum contracts — are derived from each account's detected firm and account size. You do not type them in on this page; you check them on Settings → Accounts, and that is worth doing once, because everything the guard does downstream rests on them.

Personal preferences are the limits you set for yourself on this page, and they apply across every account you trade.

The resolution rule is simple and always in your favour: the stricter number wins. Set a personal daily loss limit tighter than the firm's and yours is enforced. Set one looser and the firm's still holds — the guard will not let a preference relax a rule the firm imposed.