Almost all strapless hrms do not take continuous heart rate, and require you to touch a button with your finger to get a reading. Some new stuff is coming to market that will change this but it's an emerging technology. However, it looks like the epulse 2 is continuous? It has horrible reviews though.

I recommend getting a hrm designed to work as a cyclocomputer. Some of these will also work with a wrist strap off the bike. You really want hrm info to be easy to read to be useful on the bike.

I have a wireless Sigma I've been happy with. The chest strap doesn't really annoy me.