Bottle conditioning a semi-sweet mead is a hazardous proposition. Yeast are unpredictable and you aren’t going to be able to tell exact what the gravity will be when they stop. It could be off by a few gravity points. Unfortunately those few gravity points can be enough to seriously over-pressurize a bottle leading to flying glass from a bottle bomb. If it happen to blow at just the right time, you may spend the rest of your days with a white cane and a furry companion.
Yeast are capable of generating pressure capable of exploding bottles. It takes more than 7 atmosphere of CO2 pressure to reliable stop yeast. That’s 100+ PSI, and definitely more than beer bottles can tolerate. Champagne bottles can tolerate a lot more pressure, but even they have limits and glass shatters unpredictably (talk to any materials science engineers if you have doubts). Even Champagne makers have glass blow from time to time, and they have experience with this.
Each volume of CO2 equates to about 1.5 gravity points. If your fermentation happens to to go 2 or 3 points past where you expected, you could be in a range to have beer bottles exploding.
This is why the Method Champenoise was developed, and why they ferment things dry, then add enough fermentable sugar to achieve the desired level of carbonation, then let the yeast die under pressure (which occurs after 6-9 months) during which time they get all the yeast to settle in the neck of the bottle, after which they freeze and remove the yeast. Then, they add sugar syrup as desired to sweeten it in the bottle and recork it before the carbonation escapes. It is a tricky process, but safer than the idea you propose.
A much easier alternative is to force carbonate your semi-sweet and sweet meads.
You can bottle condition in PET plastic bottles without fear of harm.
If you insist (against advice) on trying to bottle condition something sweet in glass, at least bottle some in a PET soda bottle and monitor it. When the PET bottles start to firm up, you know the carbonation has occurred and you want to immediately stick the glass bottles in a fridge to prevent further carbonation and pressure build up. Keep those bottles cold and do not let them warm up.
I hope that helps.