I have 3 SS tikkas waiting to build on or sell. What are the “sought after advantages” of custom actions the solus doesn’t provide? There must be quite a list since you used the term “MOST”! I named 3 highly sought after advantages of custom actions that the solus does possess. “Smooth” is relative and I don’t have them in my hands to gauge that after initial break in.The short answer is that, generally, we don't "bother with custom receivers."
There are features that are interesting which Tikkas don't have - modular bolt heads, quick change barrel systems, lighter bolt lifts, etc. However, for most of us these features are weighed down by the requirement for a Remington 700 pattern trigger and its reliability/safety baggage.
For a self-professed cheapskate like yourself, focused on utility, I'd recommend selling those Solus actions (which don't even provide most of the sought-after advantages of customs, and are not terribly smooth) and focusing on the humble Tikka.
-J