The Timeless is already V-shaped. V-shaped emphasises the bass and treble and recesses the mid-range- vocals are pushed back. If you want more vocal emphasis you want something less V-shaped, not more. I also have the Galaxy Buds Pro you mention and they have far more forward mids, particularly lower mids, compared to the Timeless.
https://crinacle.com/graphs/iems/graphtool/?share=IEF_Neutral_Target,Timeless,Galaxy_Buds_Pro
Timeless do benefit from a bit of power and may sound better off the BTR5 than laptop. Good idea to get a balanced cable as it has 3-4x the power in balanced mode. I use these balanced with the BTR5, it works very well. It's unlikely to fundamentally alter the sound signature though. Distortion due to lack of power, if it exists, will primarily manifest in the very low bass, not high up in the mids.
Probably the next step up, with more mids, would be something like the Moondrop Blessing 2 ($320), or Blessing 2 Dusk ($329- my preference). If you did go for the B2 (non-Dusk) I have seen that as low as ~$272 in sales. The Dusk doesn't tend to get reduced so much. If you want closer to Timeless, with similar bass but a bit more in the mids, Dusk. Blessing 2 if you want far less bass(which in turn, will naturally emphasise the mids), and a sooner/ slightly higher (more shouty) pinna gain (upper mids).
https://crinacle.com/graphs/iems/graphtool/?share=IEF_Neutral_Target,Timeless,Dusk_S2
The new
Shuoer S12 ($129-149) which is a similar planar IEM might also be an option, it's early days and preliminary graphs suggest mids are very similar but I think I saw some people say they are more forward on this than the Timeless, that it's less V-shaped. It's looking similar, good, cheaper, maybe slightly more towards what you are looking for.