You don't need to change the head weight for that shaft if it's the same length. If you start shortening the shaft, you may want to change it for a more desirable swing weight, but it's all a personal preference.

I play the fairway woods (3 and 5) in TSi1 with tensei blue 65R shafts and +4 grams in the head weights which works well for me and matches them closer to my TSR3 driver. Given your budget situation, you can switch shafts and then play around with lead tape to get the feel and launch you want and then buy some aftermarket weights to give you a more permanent solution. Hopefully that will get you going until you have the opportunity to move up into current equipment through a good, professional fitter.

Any chance you can get access to a monitor to check launch and spin numbers? My TSi 1 started with a 40 g Ascent shaft. Then moved to a Tensai Blue R shaft to keep launch under 18 degrees and spin under 3500.
Started with a Kuro Kage R in a TSR-2. Just moved to a Hazard Red to cut spin and launch as well as tighten dispersion.

If you are launching too high with no roll out, the Speeder may be too whippy the KK may improve but still be less than ideal.

The TS2 likely would have a 60g shaft. So the Kuro Kage would still be lighter. It was designed for lower swing speeds, but Nelly Korda used it before her TM contract. If you add an +8 weight, it will change the launch characteristics. May be better, more customizable to put lead tape on so you can add weight where you want it.

The TS1 market value is somewhere around $150 same for the TS2. I'd sell the TS1 and then buy a TS2. If you fit into a regular flex, I don't think you'd see much difference between the two. Swing speed isn't much higher than the targeted 85 MPH and below for the TS1.

I think start with changing the swing weight by 1-2 weights (2-4grams). I just changed my TSR4 from 5+11 (+2) to 5+13 (+4) and now is at D5 and I feel it's made a significant difference in feel. I can feel the clubhead much better through the swing and it's made for much better ball striking.

I’m a 76 year old, 20 handicap golfer. I just acquired a TSi1 Driver. It has a 50g Mimaya Element Senior shaft.
I upgraded from 917 D2 to the TSi1. Is the TSi1 lighter? Would I need to add any weight? I’m retired and on tight budget and can’t afford to use a fitter.