Closely is the LinkedIn Automation tool which I found to be safe and cloud based. Once we set-up the automation, no need to worry about and we are set to go. There are a few features that I found to be working best like
1. Account Warmup - Warm-ups our account to keep it safe without getting banned.
2. Human-like approach, it distributes the automation throughout the day. Keeps account safe.
3. Multi-step sequence
4 - Multiple ways to fetch audience from LinkedIn like search urls, group members, event attendees, etc with just a link.
5. Closely also helps to bypass LinkedIn limits with invite via emails to get better results - Amazing feature.

There are a few features which I miss and wish to have on Closely (Few are there in their roadmap and wish to see them soon) like
1. Webhook that helps me to send emails to those who do not accept my request or reply back. This help with omni-channel approach.
2. Send personalize images using tools like Nexweave and Hyperise in message after acceptance of connection request. This takes conversion rates through the roof.

Rest I find closely to be the best and safe to use automation tool for LinkedIn. (I have been using it for more than a month and its really safe.)