We know specifically that the Aeros can't ferry them.

The wording on the platoon option is very specific: Tracked Vehicle or KV-47 (sans Aero).

Also, any vehicle with Tank Rider automatically cannot ferry squads using the Tanko option. That rules out all existing SSU tanks.

Thus:

• Can KV-3s give Tankos a ride?
• Can Grand'ma give Tankos a ride?

Thanks in advance.

No - it's not a KV-47.

Yes - it's a KV-47 (described as a modified KV-47B)