All depends on the rear bush condition, and that counts in lemforders favor I think. Would think the rear bush would last longer on lemforders than any other? Therefor adding Polly to that fitted wishbone if the front bush fails would be the cheapest, easiest, least agro option. Provided Polly can be fitted without removing the wishbone from the car of course, and the rearward bush is still useable.
Hacksawing through the bush outer whilst under the car may be awkward..... But then I tend to jack the car high enough to place ramps under the wheels ready for torquing the bolts anyway, so that would help with access....? Plus in Turks video he wisely acquired an air powered hack saw 
I drove Shakeng 's TD with pollied fronts last weekend, impressive steering and ride. I don't for see any issues with drivability at all.
He still had the roll bar bushes to fit, which I was able to examine in hand. I always imagined Polly to be very firm for some reason, something approaching nylon :-/ which they are not at all, far from it in fact, firm but surprisingly compliant... Well, suprising to me anyway :-/ 
With the roll bar bush they have to open out to the diameter of the roll bar to be fitted, they are not in two halfs but one piece. The material bends very easily much like rubber I suppose.
Re the rearward bushes, should they have failed, they are a bit of a pig to cut out, there isn't room to drill through rubber alone, there's no line of site as the bush centre spacer has a bulge in it. Several drill bits are needed if drilling through then hacksawing. However they only need 1 or 2 tons of pressure when pressing in, so may be able to welt them out with a big Sammy and suitable drift then force them in with a vice or other means, they damage easy though, so pressing may be the only viable option there, rearward bushes are easy enough to press in and out, it's the bigger front bush that's a pita to press.
Ours is similarly treated ........
Had a full WIM set-up thereafter, and it's now a different car - believe me!

Have also got poly-bushes ready to change on the anti-roll bar, even though the originals are spot-on.
Ain't fitted 'em yet, as it looks next to impossible to effect on a TD without lowering the sub-frame - and that'll inevitably mean another WIM visit!
