On Transhuman p. 204, it says that when flexbots are combined, they get to use the highest aptitude bonuses and highest maximum that all the modules have to offer. Only the best for each is used, so if you had a -5, a +5, and a +10 to SOM with a max of 20, 30, and 40 to SOM, you would get a +10 to SOM and a max SOM of 40 (the rest are not used). Of course I got thinking of taking this to the logical extreme, max out everything. That means a +15 bonus and a max of 40 to every aptitude (to all 7 aptitudes).
Using the morph creation rules, its seems that this super morph would cost at least 170 CP (assuming no other changes). At that price, its no starter morph (and it would be too expensive to take it on a mission). Of course, no single morph can have all that, so I split the bonuses among multiple flexbot modules (why not since this started as this idea started with flexbot rules).
If I really wanted to be a munchkin about it, I could drive costs down by having the different modules take penalties to other aptitudes and lower aptitude maximums (this would be not a problem because they would be cancelled out by the best bonuses). For instance, reduce the cost a +15 bonus by applying a -10 penalty to another aptitude. I might even need to apply other defects to further drive the price down, like reduce durability. That might even be favorable if I wanted to get a flexbot that is human sized (with enough durability from modules, the minimum size increases). One solution would be to make 8 modules, 7 for aptitude bonuses and 1 for aptitude maximum. If I could drive the price down to 5 CP each, then this super morph could be bought for 40 CP.
Of course, to be fair I don't think anyone should do that. I made a more fair design before I went all munchkiny. One of my other ideas was to use a few modules as possible (without trying to cheat). I ended up making 4 similar modules, all with aptitude max of 40 and 2 +15 to any aptitude. This would create waste (since there would be 6 40 aptitude maximums and 1 +15 bonus not needed), but it would keep the R&D costs low since they are all identical (R&D is supposed to cost *a lot* to do). However, the total cost for doing a super morph that way (including waste) would be 230 CP.
Anyways, there were a few observation I made when toying with this idea.
1. The design and features of a morph have nothing to do with aptitudes. Its all in the head. You could have a large flexbot, large enough that the individual modules might too small to be much more than large foot on a large flexbot. That foot could have a +15 to SOM and, according to the rules, that bonus could be used to give the the one sleeved in the flexbot a +15 to SOM. I say foot because I wanted to create an example to show that there shouldn't be possible to contribute much hardware to the mix with a flexbot that large. The only thing that could be added is data and stuff.
2. Upon double checking and triple checking the rules, I found that things that give bonuses to aptitudes (like augments and drugs) can ignore normal limits. These limits include aptitude maximums and aptitude bonuses. The only limit to this is no aptitude may be pushed beyond 40.
3. Its really expensive to give all modules the same hardware if you need all modules to have that same hardware to have its intended effect. Augmentations like chameleon skin [Low] and synthetic mask [Moderate] need all flexbot modules to have the same gear to have its intended effect. Likewise, armor gets expensive with flexbots. A very large morph with a lot of durability needs to only buy the armor once. However if you tried to do the same with a flexbot, the armor rating of the flexbot becomes the average of all modules, so you need to buy it for every module if you don't want to lose armor.