So, you're showing the imap server timings. Note the response need to be sent and parsed by the client.
Yes, and since my client is roundcube I wrote to this maillist, to solve this performance issue.
hint: you can set $config['performance_stats'] = true
mail [1.2 МБ/1.5 МБ]: 0.1386 sec mail/getunread [929 КБ/997 КБ]: 0.0092 sec (it's probably for showing counters in folders tree) mail/list [1.3 МБ/52 МБ]: 1.0174 sec