I've no experience, but here's a couple of approaches from those who do know what they're about:
Around 25, 30 years ago, Norma introduced a factory 6.5X55 'Roe Load'. IIRC, it used the usual 139 or 140gn bullet, but loaded lighter to a significantly lower MV. In any event, stalkers obviously didn't feel the need for it as it was dropped after only two or three years.
I had a conversation with Callum Ferguson of PRS Rifles many years ago about the 260. This was before the 6.5X47 Lapua was introduced which I'm told is now his first vermin/stalking cartridge recommendation. Unusually, Callum built his 260s with a very short freebore chamber designed to handle both Varmint weight/length bullets and also the lightest of the 6.5mm Nosler Partitions. My memory says 90 or 95gn, but the lightest 264 Partition today is 100gn. Whatever it was, Callum said Nosler had introduced the bullet specifically for the then almost new 260 Rem.
In any event, these PRS 260s were built around this bullet at pretty high velocities, which Callum said was effective on any UK deer species and the bullet is constructed such that it would retain the rear section intact even at the fairly high terminal velocities as well as seeing major expansion from the soft-point tipped front end. The primary object of the exercise wasn't to cope better with Roe and Muntjac rather to be able to offer near match precision in long-distance varmint bullet loads while still having a fully effective short to mid-range deer number. This seems to be using the same basic approach as your 100gn TTSX load, only you're using a different / newer technology bullet that I'm assuming doesn't need a short freebore chamber with the longer copper bullet form.