Upgrading Vivoactive 4 to Vivoactive 5

Hello,

Currently have a VA4 and am enjoying it thoroughly. I wanted to get the Garmin HRM Pro Plus chest strap to get better HR tracking + insights like my LTHR. Unfortunately, under the device compatibility it looks like the HRM Pro Plus does not support the VA 4 (only the VA 5). I was wondering if / how I could go about upgrading my current VA 4? Does Garmin do watch upgrades (in the same watch line (Vivoactive in this case)) and if so, how would one go about getting this done?

If this isn't possible, does anybody have any solutions for getting a good chest strap HRM?

Thanks in advance.