I've tried a lot of different strings with the Vcore 98 2023, which is my racket of choice. I used the 2021 version with Poly Tour Pro, but when I switched to the new 2023 version (amazing racket, btw), I started with Poly Tour Rev 1.25 in the orange color. Rev is a nice string. Maintains tension very well, felt surprisingly soft for something Yonex says is firm/firm+, and offers decent spin. However, I don't feel the price is worth it with Rev, or any other Yonex poly. Other strings I have tried that I liked for the Vcore 98 are:
1. Luxilon ALU Power 16L (Great string, but after 8 hours, just died like no other string I've ever used. Also very expensive for what you get in terms of usage.)
2. Volkl Cyclone 1.25 (Similar to PT Rev, much cheaper, good spin, took about an hour to break in, but tension maintenance not the greatest, and felt a little plasticky)
3. Solinco Confidential 1.25 (Hated this string. Felt very harsh, made my arm hurt, took 2 hours to feel playable, decent spin though)
4. Head Lynx Tour 1.25 (Nice feel, not the softest, ok spin, good durability, works in a variety of rackets, a bit on the muted side for me, which I prefer)
The most recent string I tried has become my new string of choice for the Yonex Vcore 98 2023. Luxilon 4G Soft 1.25. This string is the creme of the crop for me. It's not the softest poly as the name might suggest. It's a little softer than the original 4G, but doesn't lose tension the way a soft poly would. Great feel, above average spin potential for a round poly, great ball pocketing, and overall a solid string for the Vcore 98, or any racket really.
For reference, I'm a 5.0-5.5 level player in my late 30s with a counterpunching game, western forehand, and two handed backhand.