I believe that you are thinking of keeping a Yellowjacket close to the ground in a different manner then was intended by the other poster. The YJ is not fast for a vtol. It has range and high damage. With other vtols you can have them speed around the map high in the air and use their high movement modifier as protection. With a YJ that's likely going to get it killed unless you can force or find a target in isolation that cannot match the range of the GR.
If you cannot find an isolated target with range less then a GR it would be in the interest of the YJ to use cover as much as possible much as a mech or ground vehicle. You do not need to worry about being shot by X number of units if you can cut off their LOS, or at least find cover that will bump up the to hit number closer to what they would need to hit faster vtols buzzing out in the open.
Nobody says you need to use flank speed. Also no one said that you need to wait until you are about to make a move to have planned it out. That means you can hit flank in open areas right before needing to make a turn, then switch to cruise to make your turn during the next movement phase. The same is true for elevation changes. The YJ is going to require additional thought when compared to other vtols.
My problem with the YJ is that it seems like one of those units that will never, in a standard game, show its full potential that may only be seen in a larger scale game. I'm guessing CampaignOps has the ability to make that happen. A game that is 3x3 or larger would also make it easier for the YJ to shine as it can exert some control on a 2x2, but the smaller size map helps players compensate for failures in positioning and planning.
Typically, any VTOL unit is wasted on a small map, and slow units like the YJ have difficulty on large maps. I've typically gotten best performance on maps of 3x4 and larger, with lots of terrain when using VTOLs, because the VTOL ability to ignore certain types of terrain obstacles and cover ground quickly. (Which the Yellowjacket tends to fail to do.)
but then, I'm one of those people that in Fan Council games using Megamek, (back during FC'62) brought in ASF support and artillery. I
like big map battles with lots of conventional assets as a counter to someone else's concentrated high-BV forces on a postage-stamp.
because I make a lot of
use of flanking attacks and 'picking at the fringes' while my enemy closes...and the Yellowjacket doesn't serve that purpose well.
it isn't mobile enough.
back in the old days, (1990's and early 2000's) I was the "conventional forces guy" in most groups, and I kind of approached it somewhat scientifically, keeping notes on units, how I lost them, and how effective they were before I lost them.
If you're fighting an enemy that isn't urbanmechs (or similar) you're going to have problems using the Yellowjacket that OTHER, earlier, lighter, cheaper, less impressive looking designs have zero problems engaging.
The reason is t he same reason tht faster light 'mechs outperform slower light 'mechs. Hits that do damage do more damage than misses with higher potential damage, and a shot that misses you does less damage than a machinegun that hits you.
The Yellowjacket sits on one end of a spectrum with the other being occupied by the Cyrano-neither one is actually as effective as the fluff or the developer's devotion insists it should be. The reasons being different because they represent extremes.
The great commonality being that both designs are over-weight for the role they fill, as a direct result both become unacceptable as combat units. *(the Cyrano can be hull-killed with an LRM-5, or almost any hit, the Yellowjacket's going to drop from easy rotor hits because it can't NOT get shot down and still influence the battle, though it's more likely to crash due to psr).
In both cases, it's a unit that you have to build your whole strategy and unit around if you don't want it to fail, rather than being a unit that enhances the strategy and other units you're taking onto the map.
on this spectrum, the sweet spot is based on movement/range. Movement, because even if you're screening b ehind terrain, you need to get to a firing position without becoming one with the map, and range because when you can overlap your medium on someone else's long, at a cruise, you're more likely to inflict SOME damage than to inflict NONE damage.
ON larger maps, with less concentration of units, this becomes radically more apparent. Some speeds and all you're doing is telegraphing your target to the other side with a Yellowjacket in regular play, and it's not got the 'eyes' to find targets in double-blind.