I was thinking about planking the front end as well.
It's worth the extra effort. There's probably enough scrap in the kit sheet, but if your LMS sells balsa nip down there and get some light 1/16" sheet. Don't believe the remark on the plan about it being reserved for "expert" builders. All you need is patience and the willingness to throw bits away if you overcook it when sanding them to fit.
...strengthened the fuselage formers ready to start that.
A suggestion, cos I always find it an absolute bind getting wire UCs to sit level and get it wrong more often than I get it right. After you've done the cross-members glue a couple of v. short guide / locating strips to the back of F5. You can always cut/sand them out after the UC is fixed in place if you're obsessive about added weight.
test fit
Couple of other notes that you may, or you may not, find useful.
Use one length of cracked* strip each side for the top canopy framing rather than two bits of strip. Much easier to fit.
Bring the canopy framing fixing forward to between steps 8 & 9. Gives you a stable platform when you're fitting the UC wire in place.
Hope your back sorts itself out soon.
Cheers,
Lurk
*If this is stale buns to you I apologise. If not...put the slightest of scores in the strip and bend it gently to the angle you need. It'll crack at the score rather than break and you're left with a single piece of strip. If it's a new trick to you cut a couple of bits of test strip from the sheet scrap and play with that. When the part is glued in position smear a tiny bit of glue into the crack.