About Glissando

That indeed was the original plan when those levels got implemented. It was used that way onöly very shortly though...
In this case it probabyl won't help much, a proposed fixed exists, but needs more work, at least a rebase, but also some changes requested during code review.

After several months the priority should be increased (same logic of the management of priorities in the operating systems) otherwise the task in question will never be taken into consideration and implemented

I've passed over enough software projects by now to find this an extremely bad way of managing priorities, especially in a context where there is no obligation whatsoever to work on a specific task (which is pretty much the case in many open source projects). But even in a lot of companies after a while they simply end up with a list filled with Urgent items after which a 'Very Urgent' and 'Extremely Urgent' and whatever a higher-up can come up with.

While it makes sense to review priorities on a time-based matter, in a good schedule your critical items should always be handled first (without them, the product is unusable anyway, so no use for releasing it either). After that one should look into tackling a few high priority items (not all of them) and then look into the medium/lower wishlist to include some of those as well (to prevent starvation of those items).

Increasing priority because of time is seldom a good practice imo.

There has been some on and off discussion regarding the nature of a portamento effect within the framework of digital intruments, which no doubt will make its implementation a little more complicated than it may seem for any one particular use. A solution which suits one need could be entirely unsuitable for another. In the world of live musicians, there are (nearly) as many ways to perform portamento as there are instruments in the orchestra.

Your example of a fretted instrument is a perfect example. If the player plays in a way that the string contacts each fret, then indeed there will be a perception of the individual pitches. If they use a slide instead of their fingers (and don't depress the string all the way to the frets) the effect will be much different.

I can imagine the portamento command within MS needing to have definitions (available via the inspector) as to whether the effect is diatonic, chromatic, or sliding seamlessly from start-to-end.