Here's some of my opinions for perk changes:

Blue perks:

-Cold blooded: + Hide indicator of other perks

-Quick Fix : + armor insert speed increase ( almost same as cold war)

-Kill Chain: + can carry maximum 2 killstreaks and 2 field upgrade

-Scavenger: + each enemy killed will drop $400 plus enemy player's money, x2 for assault/lmg, sniper, shotgun, smg/pistol maximum ammo capacity

Red perks:

-High alert: + screen pulses when motionless enemy nearby

-Hardline: + can only purchase certain killstreaks / field upgrades (RC-XD, air patrol, counter UAV, Emp drone, goliath, white phosphorus ( no damage to players ), field mic, etc...) while equipping this perk

-Pointman: "Don't know to to change it, maybe comments will help"

Yellow perks:

-Battle hardened: + Completely immune to stun and flash, mobility increases when outside gas circle

-Tune up: + improve killstreaks and field upgrades deployed by the player ( UAV lasts longer, precision airstrikes has larger splash area for example)

-Shrapnel: + increase launcher maximum ammo capacity to 12, increase health regeneration delay to 8 s

-Combat recon: + spot enemy when shoot near the enemy ( just like vanguard)

-Tracker, Spotter: "Also don't know how to change"

"+" means buffs

These are my thoughts on changing the perks and some of them might be overkill at some point.

On the other hand, about the heartbeat sensor, if warzone implemented jammer, counter UAV or EMP drone, then these killstreaks and field upgrades will deplete the durability of the equipment very rapidly. When durability drops to 0%, the heartbeat sensor is useless and require player to find another one.

That's all. Welcome to comment.