I like Conquest a lot, but it is true that it often becomes a bit of a merry-go-round where the teams just cycle between taking different objectives and then immediately moving on. This can sometimes feel a bit meaningless. I think it would be nice to incentivize defending flags more.
One idea is for the rate at which you get tickets from a flag to increase the longer you've held the flag. That way, you'd often be really incentivized to defend a flag your team has held for a while. You'd also be incentivized not to immediately leave flags defenseless after you take them, because getting flags and losing them soon thereafter would not be the best way to rack up tickets. The optimal strategy would be to get and hold a manageable number of flags, rather than to just constantly attack a new flag. I think this would also make some battles for certain flags feel super meaningful (i.e. a battle to take a flag the opponent has held for quite a while could have huge consequences).
Functionally, how long your team has had the flag (and therefore how important it is to defend) could be easily shown to players by simply putting a number in the objective sign. So let's say your team has held flag A for 2 minutes and flag B for 10 minutes. The blue circles for those flags could say "A-2" and "B-10." You could get more points for taking a flag the enemy has held for a long time, and conversely you could get more points for defending that flag.
What do people think?