can lead to quite substantially less thrust than the lowest (climb 2) climb thrust setting
It would be more logical to me, if you wish to use max derate/flex, to continue at that setting until it becomes limiting with respect to climb thrust.
Dunno if that is even possible. The FMC "reduces" thrust to climb thrust setting at a predetermined height above aerodrome. You can change the setting at which height that is for all engines or one engine out, but you cannot put any other limit based on thrust in there.
Sadly we do not even get any tables concerning Vmcg/a anymore
You really don't need them per se .. look to the speed schedule tables at minimum weight. Where the speed no longer varies with weight (Vs limiting) you are either Vmca or Vmcg limiting.
Well, no speed schedule tables either. Its all in the software for take off performance calculation. Only inflight and landing tables are available for non-normal consideration. And once you get dual figure V1s on a 50t+ aircraft you begin to wonder...
when in reality it is a very flexible thing within its limitations.
Basically fixed at very low weights to Vmca limitations, then increases with Vs against weight with the proviso that a modest increase (per overspeed -Boeing, improved performance - AB) for better climb performance usually is available
Especially during low weights you have the biggest differences. For example on a lightweight -700 and a 4000m runway you can have V values in the lower 120s, but if you add assumed temperature and improved climb consideration into the mix you can end up using all of that runway with V1/Vr in the 160s and V2 in the 170s. Not really fun to fly the latter thing as you use around a minute of take off run and all of that available runway, not to mention you cannot pitch up more than 7 to 8° after liftoff because you run out of airspeed if you do.
Keeping in mind that V2 is OEI driven.
For the normal AEO takeoff, one isn't looking to peg V2, rather something modestly in excess - typically +15-25 according to AFM recommended practice for twins. Especially for the sports car twins, AEO V2 climb has its own potential for hazard and frightens the daylights out of the new passengers ..
Of course it is OEI driven. But even in the simulator during OEI practice i would be interested to see someone peg a V2 that is only 2 kts higher than Vr. Especially when the advise in the FCM is to rotate around 1/2° per second slower than during AEO take offs resulting in rotation rates around 1 to 1,5° per second. Just checked though and any speed after rotation between V2 and V2+20 is ok, so that seems to cover it.