Obviously the best is to get it right in the first place or steam and clamp, but there are times when some other trick is needed.
Much better to pad out with shavings than to rely on a big gap filled with glue.
It's like most things, you can do it well or badly, so even if the splice isn't perfect you can fiddle and fettle it by using these tricks and "get away with it" .
BUT if someone without decent skills tries to use these tricks they will probably screw them up too
.
I hate the term "expert" but if you have to use the term, my definition of an expert is "someone who can put right their own mistakes".
I've padded out a core lam with a thin sliver before now and mended breaks, splits etc.
Del
The only arbiter of acceptability is you... but you have to listen to that internal voice that says... nope... do it again.
(Failing that, listen to your wife
)