How strong is the max boost of a Rorqual?
You can simulate such things in Pyfa, which is a great tool I recommend trying.
Alternatively the EVE uni wiki has a page on this: Command Bursts - EVE University Wiki
There you can see a max level Rorq with mindlink and industrial core turns a -15% mining cycle duration mining command burst into a -61.52% version, which is 4.1 times as strong as the default command burst with zero bonuses.
Such a cycle time duration boosts the yield of all ships in fleet by a factor 1/(1-0.6152) = 2.6, or 160% extra yield.
This is only the cycle time bonus, the Rorqual also improves mining crits which adds even more yield to the fleet.
Thanks
Out of curiosity, how does this compare to a level 5 Orca?
Orca tops out at -46.50% cycle time bonus, or 87% yield bonus.
(And a Porpoise at -41.60%, or 71% yield bonus.)
Yield under a Rorqual is therefore a factor 2.6/1.87 = 1.39 better than the Orca. It’s a huge bonus, but also a bigger risk in many situations.
You could also consider not to siege your Rorqual and get a -43.95% cycle time bonus, or 78% yield bonus without being stuck on grid. It’s much less than the Rorqual’s sieged bonus and only slightly better than a sieged Porpoise, but you can do so aligned and could try to immediately warp to the safety of a POS when hostiles appear.
I did that in Fountain Space (wrong time zone) align to POS hulks web Rorqual have Higgs fitted use fleet hanger for Hulks to store ore and only compress at POS.