It would appear that the seals are leaking a bit more than desired, however, this does not mean the ALDA won't do a fine job for you. The manifold has, effectively, unlimited air, so a small leak at the ALDA seals won't affect it at all.

The only issue is whether the 4 mm Tecalan line can flow enough air to maintain boost pressure in the ALDA. If yours leaks down in five seconds, I'd be fairly confident that the Tecalan lines are up to the task.

You can confirm all of this theory as follows:

Get a boost gauge. Connect it via a T into the ALDA line. Drive the vehicle and observe the boost at the ALDA. If it is making an adequate level of boost (10-12 psi), then you don't need to worry about it.

My SD is making about 9 psi due to the wastegate adjustment. I'll fix it once the head gasket is complete.