Flexible Stacking Over Aggregated Links

[KiloBravo]

Hi,

I have two MS425 switches that I'd like to stack; these switches will be used for servers and connect directly to the core (a pair of stacked MS450 switches).

The MS425 have 2 x 40G QSFP+ interfaces for stacking *or* uplinking, no dedicated stacking ports at the rear (according to documentation) and 32 x 10G SFP+ fiber. This gives me two options:

1. Stack the switches using the 40G stack/uplink ports. Then use multiple 10G interfaces, aggregated and connected up to the core, can go up to 8 interfaces if I've read correctly. 
2. LAG the 2 x 40G interfaces and connect up to the core, giving me 80G uplinks. Then Use the 10G interfaces to stack the switches.

My question is, with option 2, am I limited to 2 x 10G interfaces to stack with? or can i aggregate multiple interfaces on each switch and then use the aggregate's as stack links?

Thanks in advance.

[BrechtSchamp]

Unfortunately stacked ports cannot be aggregated

d.

[KiloBravo]

Thanks for confirming. Looks like I'll be using the 2x40G  for up-links and 2x10G for flexible stacking then.