you're right!
by chance, I recently purchased a replica bulletproof vest that happens to have big velcro straps I can stuff the pistol in, just like an under-arm holster.
It's surprisingly comfortable and totally not planned
(also the pistol is attached to a short sling in case it falls)
I tried to make a holster for the scoped pistol, but those straps on the vest are just perfect.
in the last resort I have a very big dump pouch.