Un-amplified the Titan whips would give a marginal improvement as they are 5dbi instead of the stock 3dbi, radiation pattern is more focused, so more range rather than penetration.
Circular polarization might be better than the omni direction whips, this would be a Titan Control 2.4ghz for the Mavic (uses only the 2,4ghz frequency range)
According to the Titan website
"The Control Antenna System is a light weight quick mounted antenna for various DJI Drones. It employs circular polarization to help push through congestion. Due to its polarized nature, the Control antenna will reduce any radio interference by process known as multipathing. This blocks out unwanted radio signals and can give a much cleaner signal."
But you could save a bit of money, by not making these incremental purchases and go straight to the Cyclone 2.4ghz, I use this in all flight scenarios with the Mavic because it's amplified and has circular polarization so it covers all bases.